Migration Planning Guide

Red Hat Enterprise Linux 7

Migrating to Red Hat Enterprise Linux 7

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Lucie Maňásková

Red Hat Customer Content Services

Lenka Kimličková

Red Hat Customer Content Services

Laura Bailey

Red Hat Customer Content Services

Mark Flitter

Red Hat Customer Content Services

Abstract

This guide documents migration of systems running Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7.

Chapter 1. How to Upgrade

As of Red Hat Enterprise Linux 7.0 GA, there is one supported upgrade path: from the latest version of Red Hat Enterprise Linux 6 to the latest version of Red Hat Enterprise Linux 7.

1.1. How to upgrade from Red Hat Enterprise Linux 6

Follow the procedures in this chapter to upgrade to Red Hat Enterprise Linux 7 from Red Hat Enterprise Linux 6. The upgrade process consists of the following steps:
  1. Check that Red Hat supports the upgrade of your system. See Section 1.1.1, “Check your support status” for details.
  2. Prepare your system for upgrade. See Section 1.1.2, “Prepare your system for upgrade” for details.
  3. Check your system for problems that might affect your upgrade. See Section 1.1.3, “Check system upgrade suitability” for details.
  4. Upgrade by running the Red Hat Upgrade Tool. See Section 1.1.4, “Upgrade your system” for details.

1.1.1. Check your support status

Upgrading from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7 is supported only if your system meets the following criteria.
  • Your system is on the latest version of the Server variant of Red Hat Enterprise Linux 6 for Intel 64 and AMD64 architecture, with all packages up to date. To check, enter the following commands:
    # cat /etc/redhat-release
    Red Hat Enterprise Linux Server release 6.9 (Santiago)
    # arch
    x86_64
    # yum upgrade -y
  • Your system is registered to receive updates from Subscription Management and not RHN Classic.
  • Your system includes only the following package groups: Minimal, Base, Web Server, DHCP Server, NFS File Server (@nfs-server), and Print Server. Remove other package groups before upgrading and reinstall them when your upgrade is complete.
Check the following Knowledgebase Solution for details: https://access.redhat.com/solutions/799813.

1.1.2. Prepare your system for upgrade

Red Hat Enterprise Linux 7 is the first major release to allow in-place upgrades from the previous major version. Upgrades of this magnitude are complex and prone to error. To ensure your upgrade goes as smoothly as possible, some preparations are necessary.
Back up all data
Firstly, back up the entire system to avoid potential data loss, and test that your backup works.
Test first
Before you upgrade a production system, you should clone the system and test the upgrade procedure on the clone. This will allow you to prepare for upgrade without risking the production system.
Convert to Red Hat Subscription Management
Red Hat Enterprise Linux 7 must be registered with the Subscription Management tool (subscription-manager) rather than RHN Classic tools like rhn_register. See https://access.redhat.com/articles/433903 for details on getting started with Subscription Management.
Before it begins upgrading packages, the yum upgrade command outputs a statement about how this system receives updates. Ensure that subscription-manager and not RHN is mentioned here.
# yum upgrade
Loaded plug-ins: product-id, security, subscription-manager
...
If your Red Hat Enterprise Linux 6 system is currently registered to RHN Classic, you must first unregister from RHN Classic by following these instructions: https://access.redhat.com/solutions/11272.
Ensure only supported package groups are installed
This upgrade process supports only the following package groups: Minimal, Base, Web Server, DHCP Server, NFS File Server (@nfs-server), and Print Server. Check which package groups are installed with the yum grouplist command. Remove other package groups before upgrading and reinstall them when your upgrade is complete.
Update all packages
Once your system is registered with Subscription Management, ensure that all packages on your system are up to date by running the following commands.
# yum update -y
# reboot

1.1.3. Check system upgrade suitability

The Preupgrade Assistant checks your Red Hat Enterprise Linux 6 system for anything that might adversely affect the success of your upgrade.

1.1.3.1. Installing the Preupgrade Assistant

  1. Enable the Extras repository

    As root, enter the following command to subscribe your system to the repository containing the Preupgrade Assistant.
    If your system receives updates from Red Hat Subscription Management:
    # subscription-manager repos --enable rhel-6-server-extras-rpms
  2. Install the tool

    As root, enter the following command to install all the Preupgrade Assistant packages.
    # yum -y install preupgrade-assistant preupgrade-assistant-el6toel7

1.1.3.2. Running the Preupgrade Assistant

To run the Preupgrade Assistant, execute the following command as root.
# preupg -v
This takes a few minutes to complete.
Alternatively, if you have already configured a Preupgrade Assistant Web UI that this system can access, execute the following, replacing hostname and port with the appropriate values for your Preupgrade Assistant Web UI:
# preupg -v -u http://hostname:port/submit
See Section 1.1.3.2.1, “Configuring the Preupgrade Assistant Web UI” for instructions on setting up the web UI.
1.1.3.2.1. Configuring the Preupgrade Assistant Web UI
Preupgrade Assistant Web UI lets you upload and view pre-upgrade results through a browser-based interface. This is useful when the system you intend to upgrade is headless or does not have a graphical user environment.

Warning

Preupgrade Assistant Web UI requires a running instance of Apache Web Server (httpd) and a number of changes to the /etc/httpd/conf.d directory. If you are concerned about exposing data about your system to the network, or you want to avoid adding packages to the system you intend to upgrade, do not follow this procedure. Instead, copy the /root/preupgrade/result.html file to a machine with a graphical user interface and view it in a web browser.
  1. Install required packages

    # yum -y install httpd preupgrade-assistant-ui
  2. Change upload configuration

    Change from using the default private pre-upgrade configuration to the public configuration.
    # cd /etc/httpd/conf.d
    # cp 99-preup-httpd.conf.public 99-preup-httpd.conf
    This makes the Preupgrade Assistant Web UI available to all network interfaces on the local system, through TCP port 8099 by default.
    You can also edit the NameVirtualHost variable in the new /etc/httpd/conf.d/99-preup-httpd.conf to set a host name, if you want to access Preupgrade Assistant Web UI through a host name like preupg-ui.example.com:8099 instead of an IP address like 192.168.99.1:8099.
  3. Change firewall and SELinux configuration

    Temporarily put SELinux in permissive mode, and allow traffic through TCP port 8099.
    # setenforce 0
    # iptables -I INPUT -m state --state NEW -p tcp --dport 8099 -j ACCEPT
  4. Restart the web server

    # service httpd restart
  5. Configure or disable authentication

    In a web browser, navigate to http://192.168.99.1:8099/ (or the host name, if you specified one in Step 2). You are prompted to either enter details to create a new administrative user, or disable authentication.
You can now upload pre-upgrade test results from the system you intend to upgrade by running the preupg command with the -u http://hostname:port/submit option on that system.

1.1.3.3. Viewing results and correcting errors

When you run preupg, a summary of results is printed to standard output. Detailed results are saved to the /root/preupgrade directory as result.html by default. You can also upload results to the Preupgrade Assistant Web UI to compare multiple preupg runs as you correct potential migration issues.
Regardless of how you view the assessment results, you need to check each item for corrections that need to be made before you upgrade. Each item is printed with an exit code that indicates that item's suitability for in-place upgrade, as described in Table 1.1, “Exit Codes”.

Table 1.1. Exit Codes

Exit Code
Definition
PASS
Everything looks fine, and this item is ready to upgrade.
FAIL
Extreme upgrade risk. upgrade is not possible.
NEEDS_ACTION
High upgrade risk. Some administrator action is required before you upgrade.
NEEDS_INSPECTION
Moderate and lower risk. Upgrading should succeed, but may result in a system that is not fully functional.
FIXED
A change required for upgrade was made automatically.
INFORMATIONAL
Useful but noncritical information about this item is available in the report.
NOT_APPLICABLE
Preupgrade Assistant checked for an item that was not installed on your system.
ERROR
Something has probably gone wrong with the pre-upgrade tools. Report this type of problem to Red Hat Support.
Take note of any post upgrade tasks identified by Preupgrade Assistant; you will need to perform these after you run the Red Hat Upgrade Tool.
You should also check the Release Notes, Technical Notes, and Migration Planning Guide for items that the Preupgrade Assistant is unable to detect.

1.1.4. Upgrade your system

After you have corrected all issues reported by the Preupgrade Assistant, you are ready to use the Red Hat Upgrade Tool to upgrade your system.

Important

Running the Red Hat Upgrade tool requires you to run the Preupgrade Assistant tool as a prerequisite. If you try to run Red Hat Upgrade on your system without first running the Preupgrade Assistant, it will exit with the following error:
preupgrade-assistant has not been run

Warning

Test this process on a non-production system before you perform it on any production system.
  1. Install the tool

    # yum -y install redhat-upgrade-tool
  2. Disable active repositories

    # yum -y install yum-utils
    # yum-config-manager --disable \*
  3. Perform the upgrade

    The upgrade process requires access to Red Hat Enterprise Linux  7 packages. You can specify the location of a repository on the network or on a mounted device, or an ISO image, as shown below.
    # redhat-upgrade-tool --network <latest_RHEL_7> --instrepo repo_location
    # redhat-upgrade-tool --device device_path
    # redhat-upgrade-tool --iso iso_path
    Some packages that were in the Base package group in Red Hat Enterprise Linux 6 are no longer part of that group in Red Hat Enterprise Linux 7. You may need to configure additional repositories in order to upgrade these packages correctly.
    Refer to https://access.redhat.com/site/solutions/912213 to enable the Extras repository on the yum repository system. Then see https://access.redhat.com/site/solutions/9892 to set up a repository that you can use during your upgrade. The upgrade command for this use case would look similar to the following.
    # redhat-upgrade-tool --addrepo optional=http://host name/path/to/repo
    Some packages are not reinstalled during the upgrade process because they have no functionally equivalent replacements in Red Hat Enterprise Linux 7. Red Hat does not provide any support for these packages. To remove these packages at the end of the upgrade process, enter the following command:
    # redhat-upgrade-tool --cleanup-post
  4. Reboot

    When prompted, reboot the system.
  5. Wait for upgrade to complete

    After your system reboots, upgrade can take several minutes or several hours, depending on the number of packages to install.
  6. Perform post upgrade tasks

    Manually perform any post upgrade tasks described in the Preupgrade Assistant assessment result. See Section 1.1.3.3, “Viewing results and correcting errors” for details.
  7. Check system status

    Check that your system's subscription details have been updated as part of the upgrade process.
    # cat /etc/redhat-release
    Red Hat Enterprise Linux Server release 7.4
    # yum repolist
    Loaded plug-ins: product-id, subscription-manager
    repo id        repo name                                    status
    rhel-7-rpms    Red Hat Enterprise Linux 7 Server (RPMs)     4,323
    If the list of your repositories did not update correctly, perform the following commands:
    # subscription-manager remove --all
    # subscription-manager unregister
    # subscription-manager register
    # subscription-manager attach --pool=poolID
    # subscription-manager repos --enable=repoID
  8. Update all packages

    Ensure that all packages are up to date by running the following:
    # yum upgrade -y
    # reboot

Chapter 2. Major Changes and Migration Considerations

This chapter discusses major changes and features that may affect migration from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7. Read each section carefully for a clear understanding of how your system will be impacted by upgrading to Red Hat Enterprise Linux 7.

2.1. System Limitations

Red Hat Enterprise Linux supported system limitations have changed between version 6 and version 7.
Red Hat Enterprise Linux 7 now requires at least 1 GB of disk space to install. However, Red Hat recommends a minimum of 5 GB of disk space for all supported architectures.
AMD64 and Intel® 64 systems now require at least 1 GB of memory to run. Red Hat recommends at least 1 GB memory per logical CPU. AMD64 and Intel® 64 systems are supported up to the following limits:
  • at most 3 TB memory (theoretical limit: 64 TB)
  • at most 160 logical CPUs (theoretical limit: 5120 logical CPUs)
64-bit Power systems now require at least 2 GB of memory to run. They are supported up to the following limits:
  • at most 2 TB memory (theoretical limit: 64 TB)
  • at most 128 logical CPUs (theoretical limit: 2048 logical CPUs)
IBM System z systems now require at least 1 GB of memory to run, and are theoretically capable of supporting up to the following limits:
  • at most 3 TB memory
  • at most 101 logical CPUs
The most up to date information about Red Hat Enterprise Linux 7 requirements and limitations is available online at https://access.redhat.com/site/articles/rhel-limits. To check whether your hardware or software is certified, see https://access.redhat.com/certifications.

2.2. Installation and Boot

Read this section for a summary of changes made to installation tools and processes between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.

2.2.1. New Boot Loader

Red Hat Enterprise Linux 7 introduces the GRUB2 boot loader, which replaces legacy GRUB in Red Hat Enterprise Linux 7.0 and later. GRUB2 supports more file systems and virtual block devices than its predecessor. It automatically scans for and configures available operating systems. The user interface has also been improved, and users have the option to skip boot loader installation.
However, the move to GRUB2 also removes support for installing the boot loader to a formatted partition on BIOS machines with MBR-style partition tables. This behavior change was made because some file systems have automated optimization features that move parts of the core boot loader image, which could break the GRUB legacy boot loader. With GRUB2, the boot loader is installed in the space available between the partition table and the first partition on BIOS machines with MBR (Master Boot Record) style partition tables. BIOS machines with GPT (GUID Partition Table) style partition tables must create a special BIOS Boot Partition for the boot loader. UEFI machines continue to install the boot loader to the EFI System Partition.
The recommended minimum partition sizes have also changed as a result of the new boot loader. Table 2.1, “Recommended minimum partition sizes” gives a summary of the new recommendations. Further information is available in section 6.14.1.1 MBR and GPT Considerations of the Red Hat Enterprise Linux 7 Installation Guide.

Table 2.1. Recommended minimum partition sizes

PartitionBIOS & MBRBIOS & GPTUEFI & GPT
/boot500 MB
/10 GB
swapAt least twice the RAM. See Section 6.10.4.5. Recommended Partitioning Scheme in the Red Hat Enterprise Linux 7 Installation Guide for details.
boot loaderN/A (Installed between the partition table and the first partition)1 MB (BIOS Boot Partition)200 MB (EFI System Partition
Users can install GRUB2 to a formatted partition manually with the force option at the risk of causing file system damage, or use an alternative boot loader. For a list of alternative boot loaders, see the Red Hat Enterprise Linux 7 Installation Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.
If you have a dual-boot system, use GRUB2's operating system detection to automatically write a configuration file that can boot either operating system:
# grub2-mkconfig -o /boot/grub2/grub.cfg

Important

Note, that if you have a dual-boot that is based on using UEFI uses other mechanism than MBR legacy based one. This means that you do not need to use EFI specific grub2 command:
# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg

2.2.1.1. Default Boot Entry for Debugging

Default boot entry for systemd has been added to the /etc/grub.cfg file. It is no longer necessary to enable debugging manually. The default boot entry allows you to debug systems without affecting options at the boot time.

2.2.2. New Init System

systemd is the system and service manager that replaces the SysV init system used in previous releases of Red Hat Enterprise Linux.
systemd is the first process to start during boot, and the last process to terminate at shutdown. It coordinates the remainder of the boot process and configures the system for the user. Under systemd, interdependent programs can load in parallel, making the boot process considerably faster.
systemd is largely compatible with SysV in terms of user experience and scripting APIs. However, some exceptions do exist. See Section 2.2.2.1, “Backwards Compatibility” for details.
The move to systemd also involves a change in administration tools for Red Hat Enterprise Linux. See the systemctl man page or the Red Hat Enterprise Linux 7 System Administrator's Guide for details.
For further information about the boot process, see the Red Hat Enterprise Linux 7 Installation Guide. For further information about systemd, see the Red Hat Enterprise Linux 7 System Administrator's Guide.

2.2.2.1. Backwards Compatibility

systemd is designed to be largely compatible with SysV in terms of user experience and scripting APIs. However, there are some cases where compatibility is limited.
  • Standard /etc/init.d/servicename commands (start, stop, status) still work. However, Red Hat recommends /usr/sbin/service servicename commands, as they forward directly to systemd rather than using legacy init scripts.
  • Run level support is limited. All SysV run levels map to systemd targets; however, not all systemd targets map to SysV run levels. Some checks for the current run level will therefore return N (unknown run level). Red Hat recommends avoiding run level checks and moving to the more useful systemd targets.
  • Legacy run levels 2, 3, and 4 all map to the multi-user.target systemd target by default. Users can modify this behavior by configuring different systemd targets.
  • Services execute cleanly and do not inherit any context of the invoking user. Init scripts depending on inherited context will not work.
  • systemd does not support additional verbs in init scripts. If you require verbs other than start, stop, or status, move them to an auxiliary script.
  • Linux Standard Base header information is now fully interpreted and utilized by systemd at run time.
  • All init script operations are now subject to a timeout of 5 minutes to prevent the system from freezing because of a hanging init script.
  • systemd stops only running services; services that were not started are also not stopped during shutdown.
  • The chkconfig tool shows only SysV services and run level information, and may output misleading information. Red Hat recommends using the systemctl command instead.
  • SysV services, even those with root privileges, cannot acquire real-time scheduling when the CPUAccounting option is enabled. With CPUAccounting enabled for any service, systemd makes use of the CGroup CPU bandwidth controller globally, and subsequent sched_setscheduler() system calls terminate unexpectedly due to real-time scheduling priority. To avoid this error to recur, the CGroup cpu.rt_runtime_us option can be set for the real-time using service.
  • Services can no longer read from standart input (stdin). If you require interactive scripts, consider the minimal password querying framework supported by systemd. Further information about this functionality is available from the man page:
    $ man systemd-ask-password
  • Previous versions of Red Hat Enterprise Linux included a System z specific preinstallation script (linuxrc.s390), which started System z systems at boot time. The new init system obsoletes this preinstallation script, and System z systems now boot in the same way as AMD64, Intel® 64 and Power systems.

2.2.2.2. Systemd-debug-generator

The systemd-debug-generator is a generator for enabling a runtime debug shell and masking specific units at boot. It reads the kernel command line and understands the following three options:
systemd.mask=
If this option is specified and followed by a unit name, this unit is masked for the runtime. At boot, it is useful to hae certain units removed from the initial boot transaction for debugging system startup. This option may be specified more than once.
systemd.wants=
If this option is specified and followed by a unit name, a start job for this unit is added to the initial transaction. This is useful if you want to start one or more additional units at boot. This option may be specified more than once.
systemd.debug_shell
If this option is specified, the debug-shell.service is pulled into the boot transaction. It will spawn a debug shell on tty9 during early system startup. Note that the shell may also be turned on persistently by using a systemctl enable command.

2.2.2.3. New Installer

The Red Hat Enterprise Linux installer, Anaconda, has been redesigned and enhanced in order to improve the installation process for Red Hat Enterprise Linux 7.
The updated installer features:
  • A redesigned graphical user interface that is faster, more flexible, and requires less input from the user.
  • Support for LVM thin provisioning.
  • Installation support for btrfs. (Note, however, that btrfs is a Technology Preview in Red Hat Enterprise Linux 7.)
  • Improved localization support.
  • Support for directly formatted and not partitioned devices.
  • Support for teaming and bonding network technologies.
  • Support for automatically selecting an appropriate keyboard layout, language, and time zone. (This requires internet connectivity.) Values set based on detection are overridden by any manually set values.
  • NTP servers advertised by DHCP are now used automatically.
  • Kickstart integration for the realmd D-Bus service, Active Directory, and FreeIPA.
  • A new text mode that works on IBM System z and PowerPC systems, and serial consoles. Text mode provides a subset of the features provided by the graphical installer.
This new installer also comes with some important changes.
  • Previously, storage configuration required that the user have detailed technical knowledge of their storage system. In Red Hat Enterprise Linux 7, storage configuration has been redesigned so that users need to enter minimal detail to configure storage.
  • Anaconda now uses the inst.repo parameter to set network and other install locations instead of using the inst.root parameter.
  • Detailed package selection in the graphical installer interface has been replaced by the Software Selection screen. Software is divided up in to Environments and Addons. Users pick one environment and any number of add-ons. Kickstart installations continue to have full control over packages selected at install time.
For further information about any of these features, see the Red Hat Enterprise Linux 7 Installation Guide.

2.2.2.4. Boot parameter changes

2.2.2.4.1. Specifying boot parameters
Boot options specific to the installer are prefixed with inst. in this guide. Currently, this prefix is optional in Red Hat Enterprise Linux 7: resolution=1024x768 works exactly the same as inst.resolution=1024x768. However, this prefix is expected to become mandatory in future releases, and parameters without prefix are considered deprecated.
2.2.2.4.2. Changes to boot parameters
The new installer uses dracut to configure disks and networking. As a result, some kernel command line boot parameters have changed between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.
2.2.2.4.2.1. New parameters
inst.stage2
Specifies the location of the installation program runtime image to be loaded. The syntax is the same as the syntax of the inst.repo parameter. This option ignores everything but the image; it cannot be used to specify the location of packages.
inst.dd
Updates a driver package with a package at the location specified. This option can be used multiple times. The location syntax is the same as the location syntax of the inst.repo parameter.
inst.geoloc
Configures geolocation usage in the installer to preset the language and time zone. The default value is provider_fedora_geoip. Valid values for this parameter include the following.

Table 2.2. Geolocation values

Value
Effect
0
Disables geolocation.
provider_fedora_geoip
Uses the Fedora GeoIP API.
provider_hostip
Uses the Hostip.info GeoIP API.
inst.usefbx
Specifies that the frame buffer X driver should be used instead of a hardware specific driver. This option is equivalent to inst.xdriver=fbdev.
bootdev
Specifies the boot interface. This option is mandatory if ip is specified more than once.
inst.multilib
Configures the system for multilib packages, for example, to allow 32-bit packages to be installed on a 64-bit system.
gpt
Installs partition information into a GUID Partition Table (GPT) instead of the Master Boot Record (MBR).
inst.virtiolog
Specifies a virtio port to be used to forward logs. The default value is org.fedoraproject.anaconda.log.0. If this port exists, it will be used.
rd.dasd
Takes a Direct Access Storage Device (DASD) adaptor device bus identifier and, optionally, comma separated sysfs parameter and value pairs. Activates the DASD with the specified device bus ID and sets the mentioned sysfs parameters to the values specified. For example, rd.dasd=adaptor_id,readonly=0. This parameter can be specified multiple times to activate multiple DASDs.
rd.zfcp
Takes a SCSI over FCP (zFCP) adaptor device bus identifier, a world wide port name (WWPN), and a FCP LUN. Activates the zFCP device with the specified device bus identifier, port name, and LUN. This parameter can be specified multiple times to activate multiple zFCP devices.
rd.zfcp=0.0.4000,0x5005076300C213e9,0x5022000000000000
rd.znet
Takes a network protocol type, a comma delimited list of subchannels, and, optionally, comma delimited sysfs parameter and value pairs. Activates the System z network device driver for the specified protocol, sets up the specified subchannels, and sets the parameters specified. This parameter can be specified multiple times to activate multiple network devices.
rd.znet=qeth,0.0.0600,0.0.0601,0.0.0602,layer2=1,portname=foo
rd.znet=ctc,0.0.0600,0.0.0601,protocol=bar
2.2.2.4.2.2. Changed parameters
inst.ks.sendmac
Previously kssendmac. Adds headers to outgoing HTTP requests including the MAC addresses of all network interfaces. This is useful when using inst.ks=http to provision systems.
name server
Previously dns. Specifies the address of the name server. This option can be used multiple times.
2.2.2.4.2.3. Deprecated parameters
Options in this list are deprecated. They will still work, but there are other options which offer the same functionality. Using deprecated options is not recommended and they are expected to be removed in future releases.
updates
Specified the location of updates for the installation program. Use the inst.updates option instead.
method
Configured the installation method. Use the inst.repo= option instead.
repo
In NFS installations, specified that the target was an ISO image located on an NFS server instead of an installable tree. The difference is now detected automatically, making this option the same as inst.repo=nfs:server:/path.
dns
Configured the Domain Name Server (DNS). Use the nameserver= option instead.
netmask, gateway, hostname, ip, ipv6
These options have been consolidated under the ip option.
ip=bootif
Specified the BOOTIF option used when installing from a PXE server. This is now detected automatically.
ksdevice
Configured the network device to be used during a Kickstart installation. Different values for this parameter have been replaced with different parameters as per the following table.

Table 2.3. kickstart parameter values

Value
Current behavior
Not present
Attempt to activate all devices with DHCP, unless a device and configuration are specified with the ip or BOOTIF options.
ksdevice=link
Ignored (this is the same as the default behavior).
ksdevice=bootif
Ignored (BOOTIF is used as the default if specified).
ksdevice=ibft
Replaced with dracut option ip=ibft.
ksdevice=MAC
Replaced with BOOTIF=MAC.
ksdevice=device
Replaced with device specification in the dracut ip option.
blacklist
Used to disable specified drivers. This is now handled by the rd.driver.blacklist dracut option with the following syntax:
rd.driver.blacklist=mod1,mod2,...
nofirewire
Disabled support for the FireWire interface. You can disable the FireWire driver (firewire_ohci) by using the rd.driver.blacklist option instead:
rd.driver.blacklist=firewire_ohci
2.2.2.4.2.4. Removed parameters
The following options have been removed. They were present in previous releases of Red Hat Enterprise Linux, but they cannot be used anymore.
serial
This option forced Anaconda to use the /dev/ttyS0 console as the output. Use the console parameter to specify the /dev/ttyS0 console (or similar) instead.
essid, wepkey, wpakey
Configured wireless network access. Network configuration is now handled by dracut, which does not support wireless networking, rendering these options useless.
ethtool
Used in the past to configure additional low-level network settings. All network settings are now handled by the ip option.
gdb
Allowed you to debug the loader. Use rd.debug instead.
inst.mediacheck
Verified the installation media before starting the installation. Replaced with the rd.live.check option.
ks=floppy
Specified a diskette as the Kickstart file source. Floppy drives are no longer a supported boot medium.
display
Configured a remote display. Replaced with the inst.vnc option.
utf8
Added UTF8 support when installing in text mode. UTF8 support now works automatically.
noipv6
Disabled IPv6 support in the installation program. IPv6 is now built into the kernel so the driver cannot be blacklisted; however, it is possible to disable IPv6 using the ipv6.disable dracut option.
upgradeany
Upgrades have changed inRed Hat Enterprise Linux 7. For more information, see Chapter 1, How to Upgrade, Section 3.1.1, “Preupgrade Assistant”, and Section 3.1.2, “Red Hat Upgrade Tool”.
vlanid
Configured a VLAN device. Replaced with the dracut vlan option.

2.2.3. Changes to firstboot Implementation

Red Hat Enterprise Linux 7 replaces firstboot with the Initial Setup utility, initial-setup, for better interoperability with the new installer. Basic firstboot functionality has been moved to the installer and initial-setup.
Third-party modules written for firstboot continue to work in Red Hat Enterprise Linux 7. However, firstboot is expected to be deprecated in future releases. Maintainers of third-party modules should therefore consider updating their modules for use with the installer or the Initial Setup tool.

2.2.4. Changed mount behavior at boot

Earlier versions of Red Hat Enterprise Linux booted regardless of whether all partitions specified in /etc/fstab could be mounted. This could result in a system appearing "up" and healthy, while booting without required partitions.
To prevent this situation, in Red Hat Enterprise Linux 7, if a partition defined in /etc/fstab cannot be mounted at boot, boot fails. If a partition should not cause boot to fail in the event that it cannot be mounted, use the new nofail parameter in /etc/fstab.
/dev/critical     /critical   xfs   defaults          1  2
/dev/optional     /optional   xfs   defaults,nofail   1  2
In this example, the device mounted at /optional would not cause boot to fail if it could not be mounted successfully.

2.2.5. Changes to /etc/issue file

In the previous versions of the Red Hat Enterprise Linux, the /etc/issue file contained the product name and the release number of the machine. As of Red Hat Enterprise Linux 7, the product name and the release number have been moved into the /etc/os-release file and the first line of /etc/issue now contains an agetty escape code \S. The \S escape code expands in the console displaying a product name and the release number of the machine. The code is represented by the PRETTY_NAME variable, which is defined in the /etc/os-release file.

Important

The expansion of the \S escape code works only from the console. Using the expansion in an environment that does not support it will result in printing only "\S".
For more information about \S, see the agetty man pages.

2.3. File System Layout

Red Hat Enterprise Linux 7 introduces two major changes to the layout of the file system.
  • The /bin, /sbin, /lib and /lib64 directories are now under the /usr directory.
  • The /tmp directory can now be used as a temporary file storage system (tmpfs).
  • The /run directory is now used as a temporary file storage system (tmpfs). Applications can now use /run the same way they use the /var/run directory.

2.3.1. New layout for root file system

Traditionally, only the minimum necessary content was included in the /bin and /lib directories to avoid slowing down the boot process. Some of the utilities needed to be at the root (/) level in order to mount the /usr partition. This created a situation where other utilities spread their content over multiple levels of directories, for example, in both /bin and /usr/bin.
Red Hat Enterprise Linux 7 moves the /bin, /sbin, /lib and /lib64 directories into /usr. Because the /usr file system can now be mounted by initramfs rather than by utilities in root level directories, there is no longer a need to split package contents between the two different directory levels. This allows for a much smaller root file system, enabling systems that can more efficiently share disk space, and systems that are easier to maintain, more flexible, and more secure.
To lessen the impact of this change, the previous /bin directory is now a symbolic link to /usr/bin, /sbin to /usr/sbin, and so on.

2.3.1.1. Preparing your file system for upgrade

Warning

Note, that if /usr is on a separate partition, the in-place upgrade is not possible. If you decide to move the /usr from the separate partition, be aware that this is at your own risk.
If /var is on a separate partition, you must manually convert /var/run and /var/lock to symbolic links:
# mv -f /var/run /var/run.runmove~
# ln -sfn /run /var/run
# mv -f /var/lock /var/lock.lockmove~
# ln -sfn /run/lock /var/lock

Important

You must make sure you address all preupgrade-assistant results regarding partitioning scheme.
When your preparations are complete, see the Red Hat Enterprise Linux 7 Installation Guide for additional details on performing the upgrade process.

2.3.1.2. Verifying a successful upgrade

After performing the upgrade process, it is important to verify that the upgrade worked as expected.
  1. Check that the following symbolic links exist:
    • /bin is a symbolic link to /usr/bin
    • /sbin is a symbolic link to /usr/sbin
    • /lib is a symbolic link to /usr/lib
    • /lib64 is a symbolic link to /usr/lib64
    • /var/run is a symbolic link to /run
    • /var/lock is a symbolic link to /run/lock
    If the directories listed are symbolic links, as expected, two more checks are required.
  2. Check the output of the following find command:
    # find /usr/{lib,lib64,bin,sbin} -name '.usrmove'
    Files or directories displayed in response to this command could not be copied to /usr because a file or directory with the same name was already present in /usr. You will need to manually resolve these naming conflicts.
  3. Check the following directories for files that you want to keep:
    • /var/run.runmove~
    • /var/lock.lockmove~
If any of the directories listed are not symbolic links, you will need to follow the recovery process outlined in Section 2.3.1.3, “Recovering from a failed upgrade”.

2.3.1.3. Recovering from a failed upgrade

The upgrade process may fail for a number of reasons. Check the output of the following commands to see what went wrong:
# dmesg
# journalctl -ab --full
If no errors are visible, check that:
  • / is writable
  • /usr is writable
  • /usr mounted correctly
  • / has sufficient space
  • /usr has sufficient space
  • /var is mounted in the rhelup tool
Contact Red Hat Support if you need further assistance.

2.3.2. Changes to the /tmp directory

Red Hat Enterprise Linux 7 offers the ability to use /tmp as a mount point for a temporary file storage system (tmpfs).
When enabled, this temporary storage appears as a mounted file system, but stores its content in volatile memory instead of on a persistent storage device. No files in /tmp are stored on the hard drive except when memory is low, in which case swap space is used. This means that the contents of /tmp are not persisted across a reboot.
To enable this feature, execute the following command:
# systemctl enable tmp.mount
To disable this feature, execute the following command:
# systemctl disable tmp.mount
Red Hat recommends the following uses for the various types of temporary storage space in Red Hat Enterprise Linux 7.
  • Privileged processes, such as daemons, should use /run/processname to store temporary data.
  • Processes that store a large amount of data, or require temporary data to persist across reboots, should use /var/tmp.
  • All other processes should use /tmp to store temporary data.

2.3.3. Changes to the /run directory

Important

Preupgrade Assistant did not yet check for the effects of this change in the initial release of Red Hat Enterprise Linux 7.0. This issue was corrected in RHBA-2014:1627, available here: https://rhn.redhat.com/errata/RHBA-2014-1627.html.
Previous versions of Red Hat Enterprise Linux allowed some programs to store runtime data in the /dev directory during early boot, prior to the /var directory being mounted. Consensus between major Linux distributions is that /run should be used instead, as the /dev directory should be used only for device nodes.
Therefore, in Red Hat Enterprise Linux 7, the /run directory is a temporary file storage system (tmpfs) that bind mounts the /var/run directory. Likewise, the /run/lock directory now bind mounts the /var/lock directory. Files stored in /run and /run/lock are no longer persistent and do not survive a reboot. This means that applications must recreate their own files and directories on startup, rather than doing this once at installation time. An /etc/app_name directory would be ideal for this.
For details on how to recreate files and directories at startup, see the tmpfiles.d man page: man tmpfiles.d. For example configuration, see the configuration files in /etc/tmpfiles.d.

2.4. System Management

Read this section for a summary of changes made to system management tools and processes between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.

2.4.1. Default process maximums (ulimit)

In Red Hat Enterprise Linux 6, non-root users were restricted to a total of 1024 processes per PAM session. In Red Hat Enterprise Linux 7, this has been increased to 4096 processes per PAM session by default.
The default value is specified in the /etc/security/limits.d/*-nproc.conf file (usually /etc/security/limits.d/20-nproc.conf on Red Hat Enterprise Linux 7). If this file is not present, the maximum number of processes that a non-root user can own is determined programmatically, as described in https://access.redhat.com/solutions/218383.
You can find out the current number of processes available to non-root users per PAM session by running the ulimit -u command.

2.4.2. Configuration File Syntax

In Red Hat Enterprise Linux 6, the export command was used in configuration files to export the values defined in those files. Variables that did not use the export command were not exported and were used only as configuration values for the corresponding init script. This is an example /etc/sysconfig/sshd file:
AUTOCREATE_SERVER_KEYS=YES
export SSH_USE_STRONG_RNG=1
export OPENSSL_DISABLE_AES_NI=1
In Red Hat Enterprise Linux 6, only the values of SSH_USE_STRONG_RNG and OPENSSL_DISABLE_AES_NI were exported to the environment of the ssh daemon. The variable AUTOCREATE_SERVER_KEYS was used to tell the init script to automatically create RSA and DSA server private and public keys.
In Red Hat Enterprise Linux 7, the export command is no longer required for these values to be exported to the environment of the service being configured. Therefore the following example /etc/sysconfig/sshd file exports all three values to the environment of the ssh daemon:
AUTOCREATE_SERVER_KEYS=YES
SSH_USE_STRONG_RNG=1
OPENSSL_DISABLE_AES_NI=1

2.4.3. New Logging Framework

Red Hat Enterprise Linux 7 introduces a new logging daemon, journald, as part of the move to systemd. journald captures the following types of message for all services:
  • syslog messages
  • kernel messages
  • initial RAM disk and early boot messages
  • messages sent to standard output and standard error output
It then stores these messages in native journal files: structured, indexed binary files that contain useful metadata and are faster and easier to search.
Journal files are not stored persistently by default. The amount of data logged depends on the amount of free memory available; when the system runs out of space in memory or in the /run/log/journal directory, the oldest journal files will be removed in order to continue logging.
On Red Hat Enterprise Linux 7, rsyslog and journald coexist. The data collected by journald is forwarded to rsyslog, which can perform further processing and store text-based log files. By default, rsyslog only stores the journal fields that are typical for syslog messages, but can be configured to store all the fields available to journald. Red Hat Enterprise Linux 7 therefore remains compatible with applications and system configurations that rely on rsyslog.
For further details about the logging subsystem, see the Red Hat Enterprise Linux 7 System Administrator's Guide.

2.4.4. Localization Settings

As part of the move to the new init system, systemd, localization settings have moved from /etc/sysconfig/i18n to /etc/locale.conf and /etc/vconsole.conf.

2.4.5. Hostname Definition

In Red Hat Enterprise Linux 6, the hostname variable was defined in the /etc/sysconfig/network configuration file. In Red Hat Enterprise Linux 7, as part of the move to the new init system (systemd), the hostname variable is defined in /etc/hostname.

2.4.6. Updates to Yum

Red Hat Enterprise Linux 7 includes an updated version of yum, which includes a number of changes and enhancements. This section lists changes that may affect yum users moving from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7.
  • yum group and yum groups are now top level commands, to improve the consistency of command line yum use. For example, where previously you would use yum groupinfo, you can now use yum group info.
  • yum group list now includes additional optional parameters to alter its output. The new options are language and ids.
  • The default value for the group_command parameter in /etc/yum.conf has been changed from compat to objects. Previously, the default behavior of yum group install was to install all members of a package group and upgrade both previously installed packages and packages that had been added to the group since the previous upgrade. The new default behavior is that yum keeps track of the previously installed groups and distinguishes between packages installed as a part of the group and packages installed separately.
  • The yum-security and yum-presto plug-ins have been integrated into yum.
  • yum can now download multiple packages simultaneously.
  • yum now includes support for environment groups. This allows you to install and remove multiple package groups listed under an environment group as a single entity.
  • yum can now treat a repository as a set of packages, allowing users to treat all packages in a repository as a single entity, for example, to install or remove all packages in that repository. This capability is provided by the repository-packages subcommand.
  • yum now includes a --disableincludes option, which allows you to disable include statements defined in your configuration files. You can either disable all include statements with the all value, or disable the include statements defined for a specific repository by providing that repository identifier.
  • yum now includes an --assumeno option, which assumes that the answer to any question asked by yum is 'no'. This option overrides the --assumeyes option, but is still subject to the behavior prescribed by alwaysprompt.
For further information about yum, see the man page:
$ man yum

2.4.7. Updates to RPM Package Manager (RPM)

Red Hat Enterprise Linux 7 provides an updated version of RPM Package Manager. This update includes a number of changes to behavior that may affect migration.
  • Conflict detection is now stricter and more correct. Some packages that would have installed on Red Hat Enterprise Linux 6 may not install on Red Hat Enterprise Linux 7 because of this heightened conflict sensitivity.
  • A package that conflicts with other versions of itself can now be set up as a singleton using alternatives, so that multiple versions of a single package can be installed alongside each other.
  • If an installed package lists another package as obsolete, the second package is not installed.
  • Obsolete rules now include all matching packages regardless of other attributes such as architecture.
  • Dependency calculations no longer consider files that were not installed or files that were replaced, for example, with the --nodocs, --noconfig, or --force options, as being provided.
  • There is no longer a need to manually execute rm -f /var/lib/rpm/__db. when rebuilding a panicked (DB_RUNRECOVER) RPM Package Manager database.
  • Public keys created with OpenPGP 3 are no longer supported.
  • The --info option now outputs individual tag–value pairs per line to improve human readability. Any scripts that rely on the previous --info format need to be rewritten.
  • The spec parser is now stricter and more correct, so some previously-accepted spec files may fail to parse, or give warnings.
  • %license can now be used to mark files in the %files section of a spec file as licenses that must be installed even when --nodocs is specified.
  • Version comparison now supports the dpkg-style tilde (~) operator to handle pre-release software better. For example, foo-2.0~beta1 is considered older than foo-2.0, removing the need for tricks with the Release field to handle these common upstream version practices.
  • The automatic dependency generator has been rewritten into an extensible, customizable rule-based system with built in filtering.
This update also includes the following enhancements:
  • It is now possible to query the files installed from a package (INSTFILENAMES), the number of hard links to a file (FILENLINKS), package version control system details (VCS), and formatted dependency string shortcuts (PROVIDENEVRS, REQUIRENEVRS, CONFLICTNEVRS, OBSOLETENEVRS).
  • A number of new commands are provided, including:
    • rpmkeys
    • rpmdb
    • rpmspec
    • rpmsign
  • RPM Package Manager now includes new switches to scriptlets to enable runtime macro expansion or runtime query format expansion.
  • Pre- and post-transaction scriptlet dependencies can now be correctly expressed with Requires(pretrans) and Requires(posttrans).
  • RPM Package Manager now includes the OrderWithRequires tag to allow users to supply additional ordering information. This new tag uses the same syntax as the Requires tag, but does not generate dependencies. If mentioned packages are present in the same transaction, the ordering hints are treated like Requires when calculating transaction order.
  • Line continuations and macro expansions in spec files are no longer limited to a specified length.
  • RPM Package Manager now allows users to specify upstream version control repository information.
  • RPM Package Manager now includes an %autosetup macro to assist in automating the process of applying patches.

2.4.8. New Format of ifconfig

The format of output from the deprecated ifconfig tool has changed in Red Hat Enterprise Linux 7. Scripts that parse ifconfig output may be affected by these changes, and may need to be rewritten.
Red Hat recommends using the ip utility and its subcommands (ip addr, ip link) instead of the deprecated ifconfig tool.

2.4.9. Changes to Control Groups

The kernel uses control groups to group processes for the purpose of system resource management. Red Hat Enterprise Linux 7 introduces a number of changes to control groups.
  • Control groups are now mounted under /sys/fs/cgroup instead of /cgroup.
  • Some file systems are now mounted by default.
  • systemd does not yet fully support migration from libcgroup to systemd. As such, the cgred service should be used only to move processes to groups not managed by systemd. The cgconfig.conf file should be used to configure a control group hierarchy for file systems or file controllers not managed by systemd.
For further information about these changes, see the Red Hat Enterprise Linux 7 Resource Management Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.4.10. Changes to Kernel Crash Collection (Kdump)

The kernel crash collection tool, kdump, previously generated an initial RAMDisk (initrd) for the kdump capture kernel with a custom mkdumprd script. In Red Hat Enterprise Linux 7 the initial RAMDisk is generated with dracut, making the process of generating the initial RAMDisk easier to maintain.
As a result of this move, the following changes have been made to kdump and its configuration files.
  • The net directive is no longer supported. Users must now explicitly define either ssh or nfs.
  • The blacklist option is no longer supported. Instead, users can specify rd.driver.blacklist as a parameter in the /etc/sysconfig/kdump file of their capture kernel.
  • The default mount_root_run_init action, which was performed if dumping to an intended target failed, has been replaced by the dump_to_rootfs action. Instead of mounting the real root file system, running init scripts, and attempting to save the vmcore when the kdump service has started, this new action mounts the root file system and saves the vmcore to it immediately.
  • A new directive, dracut_args, allows you to specify additional dracut arguments when configuring kdump.
  • The debug_mem_level option is no longer included in kdump. This functionality has been moved to dracut. Users can achieve the same functionality by specifying rd.memdebug as a parameter in the /etc/sysconfig/kump file of their capture kernel.
  • The options directive was previously used to include parameters specific to the kernel module in the initial ram file system (initramfs). This method is not supported in Red Hat Enterprise Linux 7. Instead, users can specify relevant parameters in the /etc/sysconfig/kdump file of their capture kernel.
  • The link_delay and disk_timeout parameters are no longer necessary or supported, as dracut contains udev, which addresses the use case for which these parameters were previously required.
  • Any file system back-end dump targets must be mounted in the crashed kernel before the kdump service is started and the initial RAMDdisk image is created. You can achieve this by adding these targets to /etc/fstab to be automatically mounted at boot time.
  • If you specify a path, but do not specify a target, and any directory in the path that you specify is a mount point for a separate device, the vmcore is saved to the path, not the device mounted somewhere along that path. Therefore when your system reboots, and the device mounts, the vmcore is inaccessible, because the device has mounted over the top of its location. Red Hat Enterprise Linux 7 now warns about this issue when you specify a path without specifying a target.
For further details about kdump, see the Red Hat Enterprise Linux 7 Kernel Crash Dump Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/

2.4.11. Changes to usermod behavior

In Red Hat Enterprise Linux  6, the -g option of the usermod command did not manipulate group ownership. From Red Hat Enterprise Linux  7.0 to Red Hat Enterprise Linux  7.2 release, the -g option modified the group ownership of the files in the /home directory tree. Starting from Red Hat Enterprise Linux  7.3, usermod changes the group ownership of the files inside of the user’s home directory only if the home directory user ID matches the user ID being modified.

2.4.12. Changes to System accounts

The default range of IDs for system users, normal users and groups has changed in Red Hat Enterprise Linux  7 release as follows:

Table 2.4. ID layout

RangeRed Hat Enterprise Linux  6Red Hat Enterprise Linux  7
System accounts0-4990-999
User accounts500-60,0001,000-60,000
This change might cause problems when migrating to Red Hat Enterprise Linux  7 with existing users having UIDs and GIDs between 500 and 999. The default ranges of UID and GID can be manually changed in the /etc/login.defs file.

2.5. File System Formats

Read this section for a summary of changes to file system format support between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.

2.5.1. New Default File System: XFS

XFS is a very high performance, scalable file system and is routinely deployed in the most demanding applications. In Red Hat Enterprise Linux 7, XFS is the default file system and is supported on all architectures.
Ext4, which does not scale to the same size as XFS, is fully supported on all architectures and will continue to see active development and support.
Details of Red Hat support limits for XFS are available at https://access.redhat.com/site/articles/rhel-limits.
For further details about using and administering the XFS file system, see the Red Hat Enterprise Linux 7 Storage Administration Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.5.1.1. Changes to mount options

Unlike ext3 and ext4, the XFS file system enables the user_xattr and acl mount options by default. This means that you will encounter errors like the following if you include these options at either the command line or in /etc/fstab.
$ mount -o acl /dev/loop0 test
mount: wrong fs type, bad option, bad superblock on /dev/loop0,
       missing codepage or helper program, or other error
      
       In some cases useful info is found in syslog - try
       dmesg | tail or so.
Ext3 and ext4 file systems do not enable these attributes by default, and accept these options when you use the mount command or mount them with /etc/fstab.

2.5.2. Btrfs Technology Preview

Red Hat Enterprise Linux 7 introduces btrfs as a Technology Preview. Btrfs is a next generation Linux file system that offers advanced management, reliability, and scalability features. Btrfs provides checksum verification for files as well as metadata. It also offers snapshot and compression capabilities, and integrated device management.
Details of Red Hat support limits for btrfs are available at https://access.redhat.com/site/articles/rhel-limits. For more information about the level of support available for Technology Preview features, see https://access.redhat.com/site/support/offerings/techpreview/.
For further details about using and administering btrfs, see the Red Hat Enterprise Linux 7 Storage Administration Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.5.2.1. Kickstarting btrfs

In a kickstart file, to create a partition on the system, you would usually use the part command with the --fstype to create a partition that used a particular file system, like so:
part /mnt/example --fstype=xfs
However, in Red Hat Enterprise Linux 7.0 and 7.1, btrfs is treated more as a device type than a file system type. As such, btrfs is not a valid value for the --fstype parameter. Instead, use the btrfs command to define a btrfs volume, like so:
btrfs mount_point --data=level --metadata=level --label=label partitions

2.5.3. Extended file system support

Red Hat Enterprise Linux 7 introduces a unified extended file system driver that provides support for Ext2, Ext3, and Ext4.
However, Ext2 is considered deprecated as of Red Hat Enterprise Linux 7, and should be avoided if possible.
For further information about these file systems, see the Red Hat Enterprise Linux 7 Storage Administration Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.6. Physical Storage

Read this section for a summary of changes to support for physical storage and relevant configuration tools between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.

2.6.1. Changed mount behavior at boot

If a storage device is configured to mount at boot time, and that device cannot be found, or does not mount correctly, Red Hat Enterprise Linux 7 fails to boot. This is an intentional change of behavior to prevent systems from booting without important storage devices. Earlier versions of Red Hat Enterprise Linux booted regardless of whether all storage devices that were configured to mount at boot were found or mounted correctly.
If a device should not prevent the system from booting, you can mark it with the nofail option, as shown.
/dev/essential-disk			/essential			xfs	auto,defaults				0 0
/dev/non-essential-disk		/non-essential		xfs	auto,defaults,nofail		0 0

2.6.2. Using LVM snapshots as a rollback mechanism

Warning

LVM snapshots are not recommended as a primary rollback method. During an upgrade, the entire system (except user files) is overwritten. A snapshot of the system is therefore nearly the same size as the original data set.
Additionally, snapshots are more prone to error than the typical backup process, as they do not include the /boot partition.
When upgrading from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7, Red Hat recommends taking a full backup and using the backup as the primary rollback method. LVM snapshots should be used as a secondary rollback method only.
As of Red Hat Enterprise Linux 6.3, users can reserve space on their logical volumes to use as storage space for snapshots. The system can then be rolled back to the snapshot in the event that an upgrade or migration fails.
If you want to use an LVM snapshot as a secondary rollback method, you may need to add space to allow room for a complete snapshot. To add more space, you can do any of the following:
  • Add another disk. Instructions can be found in the Red Hat Enterprise Linux 7 Storage Administration Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.
  • Use parted to check for free space that is not allocated to an existing partition.
  • Use lsblk to check for empty partitions, or partitions that can be deleted to free space.
  • Use vgdisplay to check for free space in a volume group that is not allocated to a logical volume.
  • Use df to check for file systems that have free space and can be reduced, so that their logical volume or partition can be shrunk to free space.
Be aware of the following potential limitations of using LVM snapshots for rollback:
  • Snapshot size is not adjusted automatically. If your snapshot gets too large for its partition, it may become invalid, and rollback will fail. It is therefore imperative to allocate a sufficiently large space for a snapshot of your entire system, before creating that snapshot. If you need to resize a root snapshot, you will need an additional device such as a Live CD that can be used as a root device while your original root device is unmounted and resized.
  • The copy-on-write device of a snapshot is not mirrored, and will be on a single device regardless of whether your system is mirrored. If the device fails and you lose the snapshot, rollback is impossible. Red Hat recommends using a physical volume with mdraid, or using multiple snapshots to separate disks. Using multiple snapshots is slower.
  • In the event of a crash during installation, the system can become impossible to boot. In this circumstance, Red Hat recommends booting with a Live CD or PXE boot and merging your snapshot when the system has booted successfully. Merging instructions are available in the Red Hat Enterprise Linux 7 LVM documentation, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.
  • Rollback returns /var/log to the state it was in prior to upgrade. For auditing purposes, Red Hat recommends copying log files from installation to a separate location prior to initiating rollback.

2.6.3. Target Management with targetcli

Previous versions of Red Hat Enterprise Linux used tgtd for iSCSI target support and LIO, the Linux kernel target, only for Fibre-Channel over Ethernet (FCoE) targets through the fcoe-target-utils package.
Red Hat Enterprise Linux 7 now uses the LIO kernel target subsystem for FCoE, iSCSI, iSER (Mellanox InfiniBand) and SRP (Mellanox InfiniBand) storage fabrics. All fabrics can now be managed with the targetcli tool.

2.6.4. Persistent Device Names

Red Hat Enterprise Linux 7 makes the management of devices on the system easier by storing the mapping of device names (for example, sda, sdb, and others) and persistent device names (provided by udev in /dev/disk/by-*/) in kernel messages. This lets the system administrator identify the messages associated with a device, even if the device name changes from boot-to-boot.
The kernel /dev/kmsg log, which can be displayed with the dmesg command, now shows the messages for the symbolic links, which udev has created for kernel devices. These messages are displayed in the following format: udev-alias: device_name (symbolic_link symbolic link ...). For example:
udev-alias: sdb (disk/by-id/ata-QEMU_HARDDISK_QM00001)
Any log analyzer can display these messages, which are also saved in /var/log/messages through syslog.
To enable this feature add udev.alias=1 to the kernel command line in /etc/default/grub.

2.6.5. LVM cache volumes

LVM cache volume functionality is fully supported as of Red Hat Enterprise Linux 7.1. This feature allows users to create logical volumes with a small, fast device performing as a cache for larger, slower devices. See the lvmcache manual page for information on creating cache logical volumes.

2.7. Networking

Read this section for a summary of changes to networking, network protocol support and relevant configuration tools between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.

2.7.2. Updates to NetworkManager

Red Hat Enterprise Linux 7 includes an updated version of NetworkManager, which provides a number of enhancements and some new features.
  • The nmcli tool now supports editing connections with the nmcli con edit and nmcli con modify commands.
  • A new text-based user interface (nmtui) provides a streamlined console-based tool for editing network configuration and controlling network connections. This replaces the system-config-network-tui tool.
  • Previously, NetworkManager ignored network interfaces it did not recognize (interfaces other than Ethernet, Infiniband, WiFi, Bridge, Bond, and VLAN). NetworkManager now recognizes any network interface picked up by ip link, and exposes these interfaces through the D-Bus interface and clients such as nmcli. This brings NetworkManager to closer parity with tools like ip.
  • NetworkManager now non-destructively takes ownership of interfaces that it can natively configure, such as Ethernet, InfiniBand, Bridge, Bond, VLAN, and Team interfaces. If these interfaces are configured before NetworkManager starts or restarts, the previously configured connections are not interrupted. This means that the NM_CONTROLLED option is no longer required.
  • Support for checking network connectivity, hotspots and portals. This behavior is disabled by default.
  • Support for team interfaces.
  • Basic, non-native support for GRE, macvlan, macvtap, tun, tap, veth, and vxlan devices.
  • A new NetworkManager-config-server package provides defaults that are suitable for servers, such as ignoring carrier changes and not creating default DHCP connections.
  • A new dns=none configuration option for NetworkManager.conf prevents NetworkManager from making changes to the resolv.conf file.
  • Support for fast user switching.
  • Support for locking a connection to the name of an interface in addition to, or instead of, the MAC address of an interface.
This update also changes configuration file monitoring behavior. NetworkManager no longer monitors on-disk configuration files for changes. Instead, users must manually reload changed configuration files with the nmcli con reload command.

2.7.3. New Network Naming Schema

Red Hat Enterprise Linux 7 provides methods for consistent and predictable network device naming for network interfaces. These features change the name of network interfaces on a system in order to make locating and differentiating the interfaces easier.
Traditionally, network interfaces in Linux are enumerated as eth[0123...], but these names do not necessarily correspond to actual labels on the chassis. Modern server platforms with multiple network adapters can encounter non-deterministic and counter-intuitive naming of these interfaces. This affects both network adapters embedded on the motherboard (Lan-on-Motherboard, or LOM) and add-in (single and multi-port) adapters.
In Red Hat Enterprise Linux 7, systemd and udevd support a number of different naming schemes. The default behavior is to assign fixed names based on firmware, topology, and location information. This has the advantage of names that are fully automatic and fully predictable, stay fixed even if hardware is added or removed (no re-enumeration takes place), and that broken hardware can be replaced seamlessly. The disadvantage to this behavior is that the names are sometimes harder to read than the name that has previously been used, for example, enp5s0 in place of eth0.
The following naming schemes for network interfaces are now supported by udevd natively.
Scheme 1
Names incorporating Firmware or BIOS provided index numbers for on-board devices, for example, eno1. systemd names interfaces according to this scheme by default if that information from the firmware is applicable and available, with scheme 2 used as a fallback.
Scheme 2
Names incorporating Firmware or BIOS provided PCI Express hotplug slot index numbers, for example, ens1. systemd names interfaces according to this scheme by default if that information from the firmware is applicable and available, with scheme 3 used as a fallback.
Scheme 3
Names incorporating physical location of the connector of the hardware, for example, enp2s0. systemd names interfaces according to this scheme by default if that information from the firmware is applicable and available, with scheme 5 used as a fallback.
Scheme 4
Names incorporating the interface's MAC address, for example, enx78e7d1ea46da. By default, systemd does not name interfaces according to this scheme, but it can be enabled if required.
Scheme 5
The traditional unpredictable kernel-native ethX naming, for example, eth0. systemd names interfaces according to this scheme if all other methods fail.
If the system has BIOSDEVNAME enabled, or if the user has added udevd rules that change the names of kernel devices, these rules will take precedence over the default systemd policy.
For further information about this new naming system, see the Red Hat Enterprise Linux 7 Networking Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.7.4. New networking utility (ncat)

A new networking utility, ncat, replaces netcat in Red Hat Enterprise Linux 7. ncat is a reliable back-end tool that provides network connectivity to other applications and users. It reads and writes data across the network from the command line, and uses both TCP and UDP for communication.
Some of the commands in ncat differ from those originally provided by netcat, or provide different functionality with the same options. These differences are outlined in the following list.
  • The netcat -P option took a specified user name to present to a proxy server that required authentication. The ncat option for this behavior is --proxy-auth user[:pass].
  • The netcat -X option took a specified protocol for the networking utility to use when communicating with a proxy server. The ncat option for this behavior is --proxy-type.
  • The netcat -x option took an address and an optional port for the networking utility to connect to with the proxy server. The ncat option for this behavior is --proxy, which takes an IP address and an optional port, like so: --proxy host[:port].
  • The netcat -d option disabled reading from stdin. The ncat -d option allows the user to specify a wait time between read or write operations. However, ncat provides the --recv-only option, which provides similar behavior to netcat -d.
  • The netcat -i option specified an interval between lines of text sent and received, or between connections to multiple ports. The ncat -i option specifies the amount of time a connection can idle before the connection times out and is terminated. There is no equivalent in ncat to the netcat -i option.
  • The netcat -w option specifies the amount of time a connection that cannot be established can idle before the connection times out and is terminated. The ncat -w option specifies the amount of time to attempt connection before timing out.
Some options that were available in netcat do not have equivalents in ncat. ncat cannot currently perform the following.
  • Enable debugging on the socket (previously provided by netcat -D).
  • Specify the size of the TCP send and receive buffers (previously provided by netcat -I and netcat -O).
  • Specify that source or destination ports are chosen randomly (previously provided by netcat -r).
  • Enable Protection of BGP Sessions avia the TCP MD5 Signature Option, RFC 2385 (previously provided by netcat -S).
  • Specify the IPv4 type of service (previously provided by netcat -T).
  • Specify the use of UNIX domain sockets (previously provided by netcat -U).
  • Specify the routing table to be used (previously provided by netcat -V).
  • Scan for listening daemons without transmitting data.
  • Specify an interval between lines of text sent and received, or between connections to multiple ports.
The ncat utility is provided by the nmap-ncat package. For more information about ncat, see the man page:
$ man ncat

2.7.5. Changes to Postfix

Red Hat Enterprise Linux 7 upgrades postfix from version 2.6 to version 2.10. While major compatibility issues are handled by the Preupgrade Assistant on upgrading from Red Hat Enterprise Linux 6 to 7, users should be aware of the following non-fatal compatibility issues.
  • Ensure that you execute postfix stop and postfix start commands before using the postscreen daemon, to avoid problems with the pass master service.
  • Default system-supplied CA certificates are no longer added to the *_tls_CAfile or *_tls_CApath lists. This means third-party certificates no longer receive mail relay permission when permit_tls_all_clientcerts is used. If your configuration requires certificate verification, enable backwards compatible behavior by setting tls_append_default_CA = yes.
  • The verify service now uses a persistent cache with periodic cleanup enabled by default. Support for the delete and sequence operations is required. To disable the cache, specify a blank address_verify_map parameter in main.cf. To disable periodic cleanup, set address_verify_cache_cleanup_interval to 0.
  • Previously the default next-hop destination, used when a filter next-hop destination was not specified, was the value of $myhostname. The default is now the recipient domain. To change the default next-hop destination, specify default_filter_nexthop = $myhostname. In pipe-based filters, this also enables FIFO delivery order, instead of round-robin domain selection.
  • The postmulti -e destroy command no longer attempts to remove files that are created after the postmulti -e create command is executed.
  • Postfix now requests default delivery status notifications when adding a recipient with the Milter smfi_addrcpt action.
  • When the result of virtual alias expansion exceeds virtual alias recursion or expansion limits, Postfix now reports a temporary delivery error instead of silently dropping excess recipients and delivering the message.
  • The local delivery agent now keeps the owner-alias attribute of a parent alias when delivering mail to a child alias that does not have an owner-alias. This makes repeated delivery to mailing lists less likely. To enable older behavior, specify reset_owner_alias = yes.
  • The Postfix SMTP client no longer appends the local domain when looking up a DNS name without ".". To enable older behavior, specify smtp_dns_resolver_options = res_defnames. Note that this may produce unexpected results.
  • The format of the postfix/smtpd[pid]: queueid: client=host[addr] log file record has changed. When available, the before-filter client information and before-filter queue ID are now appended to the end of the record.
  • By default, postfix no longer adds an undisclosed recipient header to messages with no specified recipient. To enable older behavior, specify the following in mail.cf:
    undisclosed_recipients_header = To: undisclosed-recipients:;
  • The SASL mechanism list is now re-computed after each successful completion of STARTTLS.
  • The smtpd_starttls_timeout default value is now stress-dependent.
  • DNSBL queries with a secret in the domain name must now hide that secret from postscreen SMTP replies. For example, in main.cf, specify:
    postscreen_dnsbl_reply_map = texthash:/etc/postfix/dnsbl_reply
    In dnsbl_reply, specify a separate DNSBL name:
    # Secret DNSBL name        Name in postscreen(8) replies
    secret.zen.spamhaus.org    zen.spamhaus.org
  • All programs that use postfix VSTREAMs must be recompiled, because VSTREAM errors now use separate flags for read and write errors.
  • The default value of smtp_line_length_limit is now 999, to remain consistent with the SMTP standard.
  • Sendmail now transforms all input lines ending in <CR><LF> into UNIX format (<LF>).
  • By default, the SMTP client no longer appends AUTH=<> to the MAIL FROM command.
  • Some log messages that were previously classified as fatal are now classified as error. Log file based alert systems may need to be updated accordingly. To re-enable older behavior, set daemon_table_open_error_is_fatal to yes.
  • Newly supported long queue file names are not supported prior to Postfix 2.9. To migrate back to Postfix 2.8 or earlier, any long queue file names must be converted. To do so, stop postfix, set enable_long_queue_ids to no, and then run the postsuper command until it no longer exports queue file name changes.
  • Postfix now logs the result of successful TLS negotiation with TLS logging levels of 0. See log level descriptions in the postconf man page for details.
  • The postfix SMTP server now always checks the smtpd_sender_login_maps table.
  • The default inet_protocols value is now all (use both IPv4 and IPv6). To avoid unexpected performance loss for sites without global IPv6 connectivity, the make upgrade and postfix upgrade-configuration commands currently append inet_protocols = ipv4 to main.cf when no explicit setting is present.
  • The default smtp_address_preference value is now any (choose IPv4 or IPv6 at random).
  • The SMTP server no longer reports transcripts of sessions where a client command is rejected because a lookup table is not available. To continue receiving such reports, add the data class to the value of the notify_classes parameter.
  • A new smtpd_relay_restrictions parameter has been added. By default this enables permit_mynetworks, permit_sasl_authenticated, and defer_unauth_destination. This prevents open relay problems due to mistakes with spam filter rules in smtpd_recipient_restrictions. However, if your site has a complex mail relay policy configured under smtpd_recipient_restrictions, some mail may be incorrectly deferred. To correct this, either remove smtpd_relay_restrictions configuration and use the existing policy in smtpd_recipient_restrictions, or copy the existing policy from smtpd_recipient_restrictions to smtpd_relay_restrictions.

2.7.6. Network Protocols

Read this section for a summary of changes to network protocols between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.

2.7.6.1. Network File System (NFS)

Red Hat Enterprise Linux 7 provides support for NFS 3, NFS 4.0, and NFS 4.1. NFS 2 is no longer supported as of Red Hat Enterprise Linux 7.
NFS 4.1 provides a number of performance and security enhancements, including client support for Parallel NFS (pNFS). Additionally, a separate TCP connection is no longer required for callbacks, allowing an NFS server to grant delegations even when it cannot contact the client, for example, when NAT or a firewall interferes.
NFS 3, NFS 4.0, and NFS 4.1 are supported on the server. Support for a particular version can be enabled or disabled in the /etc/sysconfig/nfs file, by changing the value of the RPCNFSDARGS parameter. For example, RPCNFSDARGS="-N4.1 -V3" enables support for NFS 3 and disables support for NFS 4.1. For further details, see the man page:
$ man rpc.nfsd
NFS clients attempt to mount using NFS 4.0 by default, and fall back to NFS 3 if the mount operation is not successful. Default behavior can be altered by editing the /etc/nfsmount.conf file and by using command line options. See the man pages for further details.
$ man nfs
$ man nfsmount.conf
2.7.6.1.1. Parallel NFS (pNFS)
Red Hat Enterprise Linux 7 provides client support for Parallel NFS (pNFS). pNFS improves the scalability of NFS and has the potential to improve performance. When the Red Hat Enterprise Linux 7 client mounts a server that supports pNFS, that client can access data through multiple servers concurrently. Note that Red Hat Enterprise Linux 7 supports the files layout type, with objects and blocks layout types being included as a technology preview. For more information about this protocol and its capabilities, see the Red Hat Enterprise Linux 7 Storage Administration Guide.

2.7.6.2. Apache Web Server (httpd)

Red Hat Enterprise Linux 7 provides an updated version of Apache Web Server. This new version (2.4) includes some significant packaging changes as well as a number of new features.
Changed proxy configuration
Apache Web Server (httpd) configurations that use an SSL back end must now use the SSLProxyCheckPeerName directive if the SSL certificate does not match the host name configured. Previously, host names in the SSL certificate of a proxy back end were not verified.
New control mechanisms
Because Red Hat Enterprise Linux moves the system away from SysV init scripts, the commands for controlling the httpd service have changed. Red Hat now recommends the apachectl and systemctl commands instead of the service command. For example, where you would previously have run service httpd graceful, Red Hat now recommends apachectl graceful.
Changed default subcommand behavior
The systemd unit file for httpd defines different behavior for the reload and stop subcommands. Specifically, the reload subcommand now gracefully reloads the service, and the stop command now gracefully stops the service by default.
Hard coded default configuration
Previous versions of httpd provided an exhaustive configuration file that listed all configuration settings and their defaults. Many common configuration settings are no longer explicitly configured in the default configuration files; instead, default settings are now hard coded. The default configuration file now has minimal content and is easier to manage as a result. The hard coded default values for all settings are specified in the manual, which by default is installed into /usr/share/httpd.
New Multi-Processing Model modules
Previous releases of Red Hat Enterprise Linux provided several Multi-Processing Models (prefork and worker) as different httpd binaries. Red Hat Enterprise Linux 7 uses a single binary and provides these Multi-Processing Models as loadable modules: worker, prefork (default), and event. Edit the /etc/httpd/conf.modules.d/00-mpm.conf file to select which module is loaded.
Directory changes
A number of directories have moved or are no longer provided in this updated version of httpd.
  • Content previously installed in /var/cache/mod_proxy has moved to /var/cache/httpd under either the proxy or the ssl subdirectory.
  • Content previously installed in /var/www has moved to /usr/share/httpd.
  • Content previously installed in /var/www/icons has moved to /usr/share/httpd/icons. This directory contains a set of icons used with directory indices.
  • The HTML version of the httpd manual previously installed in /var/www/manual has moved to /usr/share/httpd/manual.
  • Custom multi-language HTTP error pages previously installed in /var/www/error have moved to /usr/share/httpd/error.
Changes to suexec
The suexec binary no longer has its user identifier set to root at install time. Instead, a more restrictive set of permissions is applied using file system capability bits. This improves the security of the httpd service. Additionally, suexec now sends log messages to syslog instead of using the /var/log/httpd/suexec.log file. The messages sent to syslog appear in /var/log/secure by default.
Changes to module interface compatibility
Changes to the httpd module interface mean that this updated version of httpd is not compatible with third-party binary modules built against the previous version of httpd (2.2). Such modules will need to be adjusted as necessary for the httpd 2.4 module interface, and then rebuilt. See the Apache documentation for details of the API changes in version 2.4.
Change to apxs binary location
The apxs binary used to build modules from source has moved from /usr/sbin/apxs to /usr/bin/apxs.
New and moved configuration files
Configuration files that load modules are now placed in the /etc/httpd/conf.modules.d directory. Packages that provide additional loadable modules for httpd (like the php package) add files to this directory. Any configuration files in the conf.modules.d directory are processed before the main body of httpd.conf. Configuration files in the /etc/httpd/conf.d directory are now processed after the main body of httpd.conf.
Some additional configuration files are provided by the httpd package:
  • /etc/httpd/conf.d/autoindex.conf configures mod_autoindex directory indexing.
  • /etc/httpd/conf.d/userdir.conf configures access to user directories (http://example.com/~username/). By default this access is disabled for security reasons.
  • /etc/httpd/conf.d/welcome.conf configures the "welcome page" displayed on http://localhost/ when no content is present.
Changes to configuration compatibility
This version of httpd is not compatible with the configuration syntax of the previous version (2.2). Configuration files require updates to syntax before they can be used with this updated version of httpd. See the Apache documentation for details of the syntax changes made between version 2.2 and version 2.4.

2.7.6.3. Samba

Red Hat Enterprise Linux 7 provides Samba 4, a combined set of daemons, client utilities, and Python bindings that allow communicating using SMB1, SMB2, and SMB3 protocols.
The current implementation of Kerberos does not support the Samba 4 Active Directory Domain Controller functionality. This functionality has been omitted from Red Hat Enterprise Linux 7.0, but is expected to be included in future releases. All other functionality that does not rely on the Active Directory DC is included.
Red Hat Enterprise Linux 6.4 and later provided Samba 4 as a Technology Preview, and packaged it as a series of samba4-* packages to avoid conflicting with the stable Samba 3 packages (samba-*). Since Samba 4 is now fully supported and provides a number of enhancements over Samba 3, Red Hat Enterprise Linux 7 provides Samba 4 as the standard samba-* packages. The special samba4-* packages are obsolete.
For more information about Samba, see the Red Hat Enterprise Linux 7 System Administrator's Guide and System Administrators Reference Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.7.6.4. BIND

In Red Hat Enterprise Linux 6, installing the bind-chroot package changed the ROOTDIR environment variable in /etc/sysconfig/named to point to the chroot environment location. To run the named service normally (not in the chroot environment) required either removing the bind-chroot package or manually editing the ROOTDIR environment variable in /etc/sysconfig/named file.
In Red Hat Enterprise Linux 7, installing the bind-chroot package does not change how the named service runs. Instead, it installs a new service, named-chroot, that is started and stopped separately with the systemctl command, like so.
# systemctl start named-chroot.service
# systemctl stop named-chroot.service
The named-chroot service cannot run at the same time as the named service.

2.7.7. Default product certificate

Starting from Red Hat Enterprise Linux  7.2 release, the default certificate has been added to the redhat-release packages. This default certificate is stored in the /etc/pki/product-default/ directory.
The Subscription Manager now searches for the list of the certificates in the /etc/pki/product/ directory and then in the /etc/pki/product-default/ directory. Content in the /etc/pki/product-default/ directory is provided by redhat-release packages. Any certificate in the /etc/pki/product-default/ directory that is not located in /etc/pki/product/ is considered to be installed. The default product certificates are used until Subscription Manager fetches product certificates from the subscribed channels.

2.8. Clustering and High Availability

Read this section for a summary of changes to clustering and high availability support and relevant configuration tools between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.

2.8.1. Luci replacement limitations (pcs)

In Red Hat Enterprise Linux 6, luci controlled both Red Hat Enterprise Linux 5 and Red Hat Enterprise Linux 6 high availability clusters.
Red Hat Enterprise Linux 7 removes luci and replaces it with pcs. pcs can control only Red Hat Enterprise Linux 7 pacemaker-based clusters. It cannot control Red Hat Enterprise Linux 6 rgmanager-based high availability clusters.

2.8.2. Keepalived replaces Piranha

The Load Balancer Add-On for Red Hat Enterprise Linux 7 now includes the keepalived service, which provides both the functionality available in piranha and additional functionality. piranha is therefore superseded by the keepalived service in Red Hat Enterprise Linux 7.
As a result, the configuration file and its format have changed. keepalived is configured in the /etc/keepalived/keepalived.conf file by default. Details on the configuration format and syntax expected by this file are covered in the keepalive.conf man page:
$ man keepalived.conf

2.8.3. Online migration limitations

Online migration from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7 is not supported for clusters.
Additionally, the Red Hat Enterprise Linux 6 high availability stack is not compatible with the Red Hat Enterprise Linux 7 high availability stack, so online migration is not supported from a Red Hat Enterprise Linux 6 to a Red Hat Enterprise Linux 7 high availability cluster.

2.8.4. New resource manager (Pacemaker)

As of Red Hat Enterprise Linux 7, rgmanager and cman are replaced by pacemaker and corosync.
Pacemaker is a high availability resource manager with many useful features.
  • Detection and recovery from machine and application-level failures.
  • Support for many redundancy configurations.
  • Support for quorate and resource-driven clusters.
  • Configurable strategies for dealing with quorum loss (when multiple machines fail).
  • Support for specifying application startup and shutdown ordering, regardless of which machine the applications are on.
  • Support for specifying that applications must or must not run on the same machine.
  • Support for specifying that an application should be active on multiple machines.
  • Support for multiple modes for applications, such as master and slave.
  • Provably correct responses to any failure or cluster state.
  • Responses to any situation can be tested offline, before the situation exists.
For further information about Pacemaker, see the Red Hat Enterprise Linux 7 High Availability Add-On documentation available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.8.5. New feature: resource agents

Red Hat Enterprise Linux 7 introduces resource agents that work with the Pacemaker resource manager. Resource agents abstract cluster resources and provide a standard interface for managing resources in a cluster environment. For further information about the resource agents available in Red Hat Enterprise Linux 7, see the Red Hat Enterprise Linux 7 High Availability Add-On documentation available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.
Support for IBM DB2 resource agents to drive and manage DB2 as cluster resource in High Available environments has been added in Red Hat Enterprise Linux 7.2.

2.8.6. Changed quorum implementation

qdiskd, as it was shipped in Red Hat Enterprise Linux 6, has been removed from Red Hat Enterprise Linux 7. The new quorum implementation is provided by votequorum, which is included in the corosync package, and which has been extended to replace qdiskd for most use cases. The extensions (wait_for_all, auto_tie_breaker and last_man_standing) are fully documented in the votequorum.5 man page.
$ man 5 votequorum

2.9. Desktop

Read this section for a summary of changes to supported desktop user environments between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.
This section covers only the major changes that users can expect from the new desktop environments in Red Hat Enterprise Linux 7. For detailed information, see the Red Hat Enterprise Linux 7 Desktop Migration and Administration Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.9.1. New Default Desktop Environment (GNOME Classic)

GNOME Classic is the default session of the GNOME 3 desktop environment on Red Hat Enterprise Linux 7. This environment is provided as a set of extensions to the GNOME 3 desktop environment, and includes its powerful new features while retaining the familiar look and feel of GNOME 2.
In GNOME Classic, the user interface has two major components:
The top bar
This bar across the top of the screen displays the Applications and Places menus.
The Applications menu gives the user access to applications on the system, which are organized into a number of categories on the menu. This menu also provides access to the new Activities Overview, which lets you easily view your open windows, workspaces, and any messages or system notifications.
The Places menu is displayed next to the Applications menu on the top bar. It gives the user quick access to important folders, for example Downloads or Pictures.
The taskbar
The taskbar is displayed at the bottom of the screen, and features a window list, a notification icon, and a short identifier for the current workspace and the total number of available workspaces.
For a complete guide to GNOME Classic and its features, as well as the other desktop environments available in Red Hat Enterprise Linux 7, see the Red Hat Enterprise Linux 7 Desktop Migration and Administration Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.9.2. New Desktop Environment (GNOME 3)

Red Hat Enterprise Linux 7 also supports the GNOME 3 session of the GNOME 3 desktop environment. This environment is designed for ease-of-use and user productivity. It provides great integration with online document storage services, calendars, and contact lists, so that you are always up to date.
In GNOME 3, the user interface has three major components:
The top bar
This horizontal bar at the top of the screen provides access to some basic GNOME Shell functions, such as the Activities Overview, clock, calendar, system status icons, and the system menu.
The Activities Overview
The Activities Overview lets you easily view your open windows, workspaces, and any messages or system notifications. The search bar is the easiest way to find your files, launch applications, or open configuration tools. The dash on the left-hand side shows your favourite applications, so you can access your most frequently used tools faster.
The message tray
The message tray appears as a bar across the bottom of your screen. It shows pending notifications, so you always know exactly what is happening on your system.
For a complete guide to GNOME 3 and its features, as well as the other desktop environments available in Red Hat Enterprise Linux 7, see the Red Hat Enterprise Linux 7 Desktop Migration and Administration Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.9.3. KDE Plasma Workspaces (KDE)

Red Hat Enterprise Linux 7 provides version 4.10 of KDE Plasma Workspaces (KDE), previously known as K Desktop Environment. This updated version of KDE provides a number of enhancements, including the following:
  • A polished, consistent look and feel with the default Oxygen style.
  • An updated notification system (movable and closable notifications, with speed graphs) with progress visualized in the panel.
  • Workspace configuration now available in System Settings.
  • The Activity Manager provides the ability to add, remove, save, restore, and switch between Activities.
  • Optimizations to core and user interface elements for better performance.
  • Adaptive power management, with a simplified user interface and easy profile switching.
  • A new Print Manager, which simplifies printer configuration and provides fast, accurate reporting on printer status.
  • An updated Dolphin File Manager with navigation buttons, tabbed browsing, and improvements to metadata handling.
  • An updated terminal emulator (Konsole) with improved tab and window control and improved interoperability.
  • A new display manager, KScreen, which automatically can remember and restore display configuration, including resolution and relative position.
  • A new applet, Plasma Network Manager, which makes it easy to control your network and configure network connections.
However, users should note that Kmail is no longer included in Red Hat Enterprise Linux 7.

2.10. Developer Tools

Read this section for a summary of updates to developer tool support and changes that may affect developers between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.

2.10.1. Red Hat Developer Toolset

Red Hat Developer Toolset provides access to the latest stable versions of open source development tools on a separate, accelerated life cycle. It is available to Red Hat customers with an active Red Hat Developer subscription.
Red Hat Developer Toolset 2 does not currently support developing applications on Red Hat Enterprise Linux 7. However, Red Hat Developer Toolset does support developing applications on Red Hat Enterprise Linux 6, for deployment on supported minor releases of Red Hat Enterprise Linux 6 or Red Hat Enterprise Linux 7.

2.10.2. Compatibility Libraries

Red Hat Enterprise Linux 7 contains some compatibility libraries that support interfaces from previous releases of Red Hat Enterprise Linux. These libraries are included in accordance with Red Hat’s Compatibility Policy, and at Red Hat’s discretion. For further details, see the Red Hat Enterprise Linux 7: Application Compatibility Guide.
The following compatibility libraries are included in Red Hat Enterprise Linux 7.

Table 2.5. Compatibility libraries

Library
Last release where this interface was the default
compat-db47
Red Hat Enterprise Linux 6
compat-libcap1
Red Hat Enterprise Linux 5
compat-libf2c-34
Red Hat Enterprise Linux 4
compat-libgfortran-41
Red Hat Enterprise Linux 5
compat-openldap
Red Hat Enterprise Linux 5
libpng12
Red Hat Enterprise Linux 5
openssl098e
Red Hat Enterprise Linux 5
compat-dapl
Red Hat Enterprise Linux 5
compat-libtiff3
Red Hat Enterprise Linux 6
compat-libstdc++-33
Red Hat Enterprise Linux 3 (in optional repository only)
Red Hat Enterprise Linux 7 also includes the compat-gcc-44 and compat-gcc-44-c++ packages, which represent the system compiler shipped with Red Hat Enterprise Linux 6, and can be used along with the compat-glibc package for building and linking legacy software.

2.11. Security and Access Control

Read this section for a summary of changes to security, access control, and relevant configuration tools between Red Hat Enterprise Linux 6 and Red Hat Enterprise Linux 7.

2.11.1. New firewall (firewalld)

In Red Hat Enterprise Linux 6, firewall capabilities were provided by the iptables utility, and configured either at the command line or through the graphical configuration tool, system-config-firewall. In Red Hat Enterprise Linux 7, firewall capabilities are still provided by iptables. However, administrators now interact with iptables through the dynamic firewall daemon, firewalld, and its configuration tools: firewall-config, firewall-cmd, and firewall-applet, which is not included in the default installation of Red Hat Enterprise Linux 7.
Because firewalld is dynamic, changes to its configuration can be made at any time, and are implemented immediately. No part of the firewall needs to be reloaded, so there is no unintentional disruption of existing network connections.
The primary differences between the firewall in Red Hat Enterprise Linux 6 and 7 are:
  • Firewalld configuration details are not stored in /etc/sysconfig/iptables. Instead, configuration details are stored in various files in the /usr/lib/firewalld and /etc/firewalld directories.
  • Where the firewall system in Red Hat Enterprise Linux 6 removed and re-applied all rules every time a configuration change was made, firewalld only applies the configuration differences. As a result, firewalld can change settings during runtime without losing existing connections.
For additional information and assistance configuring the firewall in Red Hat Enterprise Linux 7, see the Red Hat Enterprise Linux 7 Security Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.11.1.1. Migrating rules to firewalld

Important

If you are using Red Hat Enterprise Linux 7 with another Red Hat product, such as Red Hat Enterprise Linux OpenStack Platform, it may be more appropriate to keep using iptables or ip6tables instead of moving to firewalld.
If you are uncertain which firewall utility to use, check your product documentation or contact Red Hat Support.
Instructions on how to disable firewalld and continue using iptables or ip6tables are available here: https://access.redhat.com/articles/1229233.
Red Hat Enterprise Linux 6 provided two methods of firewall configuration:
  • Use the graphical system-config-firewall tool to configure rules. This tool stored its configuration details in the /etc/sysconfig/system-config-firewall file, and created configuration for the iptables and ip6tables services in the /etc/sysconfig/iptables and /etc/sysconfig/ip6tables files.
  • Manually edit the /etc/sysconfig/iptables and /etc/sysconfig/ip6tables files (either from scratch, or editing an initial configuration created by system-config-firewall).
If you configured your Red Hat Enterprise Linux 6 firewall with system-config-firewall, after you upgrade your system and install firewalld, you can use the firewall-offline-cmd tool to migrate the configuration in /etc/sysconfig/system-config-firewall into the default zone of firewalld.
$ firewall-offline-cmd
However, if you manually created or edited /etc/sysconfig/iptables or /etc/sysconfig/ip6tables, after you install firewalld, you must either create a new configuration with firewall-cmd or firewall-config, or disable firewalld and continue to use the old iptables and ip6tables services. For details about creating new configurations or disabling firewalld, see the Red Hat Enterprise Linux 7 Security Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.11.2. Changes to PolicyKit

Previously, PolicyKit used key value pairs in .pkla files to define additional local authorizations. Red Hat Enterprise Linux 7 introduces the ability to define local authorizations with JavaScript, allowing you to script authorizations if necessary.
polkitd reads .rules files in lexicographic order from the /etc/polkit-1/rules.d and /usr/share/polkit-1/rules.d directories. If two files share the same name, files in /etc are processed before files in /usr. When the old .pkla files were processed, the last rule processed took precedence. With the new .rules files, the first matching rule takes precedence.
After migration, your existing rules are applied by the /etc/polkit-1/rules.d/49-polkit-pkla-compat.rules file. They can therefore be overridden by .rules files in either /usr or /etc with a name that comes before 49-polkit-pkla-compat in lexicographic order. The simplest way to ensure that your old rules are not overridden is to begin the name of all other .rules files with a number greater than 49.
For further information about this, see the Red Hat Enterprise Linux 7 Desktop Migration and Administration Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

2.11.3. Changes to user identifiers

In Red Hat Enterprise Linux 6, the base user identifier was 500. In Red Hat Enterprise Linux 7, the base user identifier is now 1000. This change involves replacing the /etc/login.defs file during the upgrade process.
If you have not modified the default /etc/login.defs file, the file is replaced during upgrade. The base user identifier number is changed to 1000, and new users will be allocated user identifiers at and above 1000. User accounts created before this change retain their current user identifiers and continue to work as expected.
If you have modified the default /etc/login.defs file, the file is not replaced during upgrade, and the base user identifier number remains at 500.

2.11.4. Changes to libuser

As of Red Hat Enterprise Linux 7, the libuser library no longer supports configurations that contain both the ldap and files modules, or both the ldap and shadow modules. Combining these modules results in ambiguity in password handling, and such configurations are now rejected during the initialization process.
If you use libuser to manage users or groups in LDAP, you must remove the files and shadow modules from the modules and create_modules directives in your configuration file (/etc/libuser.conf by default).

2.11.5. Changes to opencryptoki key store

Previous versions of Red Hat Enterprise Linux used the opencryptoki key store version 2, which encrypted private token objects with a secure key in hardware. Red Hat Enterprise Linux 7 uses version 3, which encrypts private token objects with a clear key in software. This means that private token objects created by version 2 must be migrated before they can be used with version 3.
To migrate private token objects, perform the following procedure:
  1. Update software

    Ensure your version of opencryptoki is up to date.
    # yum update -y opencryptoki
  2. Verify the slot number of your token

    Use pkcsconf to determine the slot number of the token. Run the following commands as root:
    # pkcsconf -s
    # pkcsconf -t
    Note the slot number of your token. The slot description will end with (CCA). The information field will identify the token as the IBM CCA Token.
  3. Stop interface access

    Stop the pkcsslotd service and any opencryptoki processes.
    # systemctl stop pkcsslotd.service
    Use the following command to identify processes to stop with the kill utility, and then terminate the appropriate processes.
    # ps ax | grep pkcsslotd
  4. Back up the data store

    Before you migrate, back up the CCA data store (the directory in which your tokens are stored, normally /var/lib/opencryptoki/ccatok). For example, make a copy of the directory.
    # cp -r /var/lib/opencryptoki/ccatok /var/lib/opencryptoki/ccatok.backup
  5. Run the migration utility

    Change to the /var/lib/opencryptoki/ccatok directory and run the migration utility.
    # cd /var/lib/opencryptoki/ccatok
    # pkcscca -m v2objectsv3 -v
    When prompted, provide your Security Officer (SO) PIN and User PIN.
  6. Remove outdated shared memory file

    Remove the /dev/shm/var.lib.opencryptoki.ccatok file manually, or reboot the system.
    # rm /dev/shm/var.lib.opencryptoki.ccatok
  7. Go back to an operational interface access

    Start the pkcsslotd service again.
    # systemctl start pkcsslotd.service
If you encounter problems with the migration, check the following:
  • Ensure you are running the commands as root, and that root is a member of the pkcs11 group.
  • Ensure that the pkcsconf utility is in either the /usr/lib/pkcs11/methods/ directory or the /usr/sbin/ directory.
  • Ensure that the token data store is in the /var/lib/opencryptoki/ccatok/ directory.
  • Ensure that you have supplied a slot number and that the slot number is correct.
  • Ensure that your Security Officer (SO) PIN and User PIN are correct.
  • Ensure that you have write access to the current directory.

Chapter 3. Changes to packages, functionality, and support

Read this chapter for information about changes to the functionality or to packages provided in Red Hat Enterprise Linux 7, and changes to the support of said packages.

3.1. New Packages

This section describes notable packages now available in Red Hat Enterprise Linux 7.

3.1.1. Preupgrade Assistant

The Preupgrade Assistant (preupg) checks for potential problems you might encounter with an upgrade from Red Hat Enterprise Linux 6 to Red Hat Enterprise Linux 7 before making any changes to your system. This helps you assess your chances of successfully upgrading to Red Hat Enterprise Linux 7 before the actual upgrade process begins.
The Preupgrade Assistant assesses the system for possible in-place upgrade limitations, such as package removals, incompatible obsoletes, name changes, deficiencies in some configuration file compatibilities, and so on. It then provides the following:
  • System analysis report with proposed solutions for any detected migration issues.
  • Data that could be used for "cloning" the system, if the in-place upgrade is not suitable.
  • Post-upgrade scripts to finish more complex issues after the in-place upgrade.
Your system remains unchanged except for the information and logs stored by the Preupgrade Assistant.
For detailed instructions on how to obtain and use the Preupgrade Assistant, see Section 1.1.3, “Check system upgrade suitability”.

3.1.2. Red Hat Upgrade Tool

The new Red Hat Upgrade Tool is used after the Preupgrade Assistant, and handles the three phases of the upgrade process:
  • Red Hat Upgrade Tool fetches packages and an upgrade image from a disk or server, prepares the system for the upgrade, and reboots the system.
  • The rebooted system detects that upgrade packages are available and uses systemd and yum to upgrade packages on the system.
  • Red Hat Upgrade Tool cleans up after the upgrade and reboots the system into the upgraded operating system.
Both network and disk based upgrades are supported. For detailed instructions on how to upgrade your system, see Chapter 1, How to Upgrade.

3.1.3. Chrony

Chrony is a new NTP client provided in the chrony package. It replaces the reference implementation (ntp) as the default NTP implementation in Red Hat Enterprise Linux 7. However, it does not support all features available in ntp, so ntp is still provided for compatibility reasons. If you require ntp, you must explicitly remove chrony and install ntp instead.
Chrony's timekeeping algorithms have several advantages over the ntp implementation.
  • Faster, more accurate synchronization.
  • Larger range for frequency correction.
  • Better response to rapid changes in clock frequency.
  • No clock stepping after initial synchronization.
  • Works well with an intermittent network connection.
For more information about chrony, see the Red Hat Enterprise Linux 7 System Administrators Guide or System Administrators Reference Guide, available from http://access.redhat.com/site/documentation/Red_Hat_Enterprise_Linux/.

3.1.4. HAProxy

HAProxy is a TCP/HTTP reverse proxy that is well-suited to high availability environments. It requires few resources, and its event-driven architecture allows it to easily handle thousands of simultaneous connections on hundreds of instances without risking the stability of the system.
For more information about HAProxy, see the man page, or consult the documentation installed along with the haproxy package in the /usr/share/doc/haproxy directory.

3.1.5. Kernel-tools

The kernel-tools package includes a number of tools for the Linux kernel. Some tools in this package replace tools previously available in other packages. See Section 3.3, “Deprecated Packages” and Section 3.2, “Package Replacements” for details.

3.1.6. NFQUEUE (libnetfilter_queue)

Red Hat Enterprise Linux 7.1 provides the libnetfilter_queue package. This library enables the NFQUEUE iptables target, which specifies that a listening user-space application will retrieve a packet from a specified queue and determine how that packet will be handled.

3.1.7. SCAP Security Guide

The scap-security-guide package provides security guidance, baselines, and associated validation mechanisms for the ​Security Content Automation Protocol (SCAP). Previously, this package was only available through the EPEL repository (Extra Packages for Enterprise Linux). As of Red Hat Enterprise Linux 7.1, scap-security-guide is available in the Red Hat Enterprise Linux 7 Server (RPMS) repository.

3.1.8. Red Hat Access GUI

Red Hat Access GUI is a desktop application, which lets you find help, answers, and utilize diagnostic services using Red Hat Knowledgebase, resources, and functionality. If you have an active account on the Red Hat Customer Portal, you can access additional information and tips of the Knowledgebase easily browsable by keywords. Red Hat Access GUI is already installed if you select to have the GNOME Desktop installed.
For more information on the benefits, installation, and usage of this tool, see Red Hat Access GUI.

3.2. Package Replacements

This section lists packages that have been removed from Red Hat Enterprise Linux between version 6 and version 7 alongside functionally equivalent replacement packages or alternative packages available in Red Hat Enterprise Linux 7.

Table 3.1. Replaced packages

Removed package
Replacement/Alternative
Notes
vconfig
iproute (ip tool)
Not fully compatible.
module-init-tools
kmod
 
openoffice.org
libreoffice
 
man
man-db
 
ext2 and ext3 filesystem driver
ext4 filesystem driver
 
openais
corosync
Functionality wrapped by the Red Hat Enterprise Linux HA stack.
jwhois
whois
Output format differs.
libjpeg
libjpeg-turbo
 
gpxe
ipxe
Fork of gpxe.
cpuspeed
kernel, kernel-tools (cpupower, cpupower.service)
Now configured in /etc/sysconfig/cpupower. No longer includes user-space scaling daemon; use kernel governors if necessary.
nc
nmap-ncat
 
procps
procps-ng
 
openswan
libreswan
 
arptables_jf
arptables
 
gcj
OpenJDK
Do not compile Java apps to native code with gcj.
32-bit x86 as installation architecture
AMD64 and Intel 64
Applications will still run with compatibility libraries. Test your applications on 64-bit Red Hat Enterprise Linux 6. If 32-bit x86 boot support is required, continue to use Red Hat Enterprise Linux 6.
Power 6 PPC support
 
Continue to use Red Hat Enterprise Linux 5 or Red Hat Enterprise Linux 6
Matahari
CIM-based management
 
ecryptfs
Use existing LUKS/dm-crypt block-based encryption
Migration is not available for encrypted file systems; encrypted data must be recreated.
evolution-exchange
evolution-mapi/evolution-ews
 
TurboGears2 web application stack
 
 
openmotif22
motif
Rebuild applications against the current Motif version.
webalizer web anayltics tool
 
Other web analytics tools are superior.
compiz window manager
gnome-shell
 
Eclipse developer toolset
 
Eclipse is now offered in the Developer Toolset offering.
Qpid and QMF
 
Qpid and QMF are available in the MRG offering.
amtu
 
Common Criteria certifications no longer require this tool.
pidgin frontends
empathy
 
perl-suidperl
perl
This functionality has been removed in upstream perl.
pam_passwdqc, pam_cracklib
libpwquality, pam_pwquality
Not fully compatible.
HAL library and daemon
udev
 
ConsoleKit library and daemon
systemd
Not fully compatible.
system-config-network
nm-connection-editor, nmcli
 
thunderbird
evolution
 
system-config-firewall
firewalld
 
busybox
normal utilities
 
KVM/virt packages (in ComputeNode)
KVM/virt equipped variant such as a Server variant
 
abyssinica-fonts
sil-abyssinica-fonts 
axisjava-1.7.0-openjdk 
ccspcsNot fully compatible.
cjkuni-fonts-commoncjkuni-uming-fonts 
classpath-jafjava-1.7.0-openjdk 
classpath-mailjavamailNot fully compatible.
cmancorosync 
control-center-extracontrol-center 
db4-cxxlibdb4-cxx 
db4-devellibdb4-devel 
db4-utilslibdb4-utils 
desktop-effectscontrol-center 
DeviceKit-powerupowerNot fully compatible.
dracut-kerneldracut 
eggdbusglib2Not fully compatible.
fcoe-target-utilstargetcliSee Section 2.6.3, “Target Management with targetcli” for details.
febootstrapsupermin 
gcc-javajava-1.7.0-openjdk-devel 
GConf2-gtkGConf2 
gdm-plugin-fingerprintgdm 
gdm-plugin-smartcardgdm 
gdm-user-switch-appletgnome-shellNot fully compatible.
geronimo-specsgeronimo-parent-poms 
geronimo-specs-compatgeronimo-jms, geronimo-jtaNot fully compatible.
gimp-help-browsergimpNot fully compatible.
gnome-appletsgnome-classic-sessionNot fully compatible.
gnome-keyring-develgnome-keyring 
gnome-maggnome-shellNot fully compatible.
gnome-python2-appletpygtk2Not fully compatible.
gnome-speechspeech-dispatcherNot fully compatible.
gpxe-roms-qemuipxe-roms-qemu 
halsystemdNot fully compatible.
hal-develsystemd-develNot fully compatible.
ibus-gtkibus-gtk2 
ibus-table-cangjieibus-table-chinese-cangjie 
ibus-table-erbiibus-table-chinese-erbi 
ibus-table-wubiibus-table-chinese-wubi-haifeng 
jakarta-commons-netapache-commons-net 
java-1.5.0-gcjjava-1.7.0-openjdk, java-1.7.0-openjdk-headlessNot fully compatible.
java-1.5.0-gcj-develjava-1.7.0-openjdk-develNot fully compatible.
java-1.5.0-gcj-javadocjava-1.7.0-openjdk-javadocNot fully compatible.
junit4junit 
jwhoiswhois 
kabi-whitelistskernel-abi-whitelists 
kdeaccessibility-libskdeaccessibility 
kdebase-develkde-baseapps-devel 
kdebase-workspace-wallpaperskde-wallpapers 
kdelibs-experimentalkdelibs 
kdesdk-libskate-libs, kdesdk-kmtrace-libs, kdesdk-kompareNot fully compatible.
kdesdk-utilskdesdk-poxml 
krb5-auth-dialoggnome-online-accountsNot fully compatible.
lldpad-libslldpad 
lslkutil-linuxNot fully compatible.
lucipcsSee Section 2.8, “Clustering and High Availability” for details.
man-pages-ukman-pages 
mingettyutil-linuxNot fully compatible.
modclusterpcsNot fully compatible.
mod_perlmod_fcgidNot compatible with httpd 2.4.
m17n-contrib-*m17n-contrib 
m17n-db-*m17n-db, m17n-db-extras 
NetworkManager-gnomenm-connection-editor, network-manager, applet 
nss_dbglibcNot fully compatible.
openaiscorosync 
openaislibcorosynclib 
openaislib-develcorosynclib-devel 
PackageKit-gtk-modulePackageKit-gtk3-moduleNot fully compatible.
polkit-desktop-policypolkit 
pulseaudio-libs-zeroconfpulseaudio-libsNot fully compatible.
qt-sqliteqt 
rdesktopxfreerdp 
Red_Hat_Enterprise_Linux-Release_Notes-6-*Red_Hat_Enterprise_Linux-Release_Notes-7-* 
redhat-lsb-compatredhat-lsb-core 
rgmanagerpacemakerSee Section 2.8, “Clustering and High Availability” for details.
rhythmbox-upnprhythmbox 
riccipcsSee Section 2.8, “Clustering and High Availability” for details.
samba4*samba*See Section 2.7.6.3, “Samba” for details.
sbm-cim-clientsbm-cim-client2Not fully compatible.
scsi-target-utilstargetcliSee Section 2.6.3, “Target Management with targetcli” for details.
seekwatcheriowatcher 
spice-clientvirt-viewerNot fully compatible.
system-config-lvmgnome-disk-utilityNot fully compatible.
texlive-*texlive 
tex-cm-lgctexlive-cm-lgc 
tex-kerkistexlive-kerkis 
texlive-texmf-dvipstexlive-dvips 
texlive-texmf-latextexlive-latex 
tomcat6tomcat 
tomcat6-el-2.1-apitomcat-el-2.2-api 
tomcat6-jsp-2.1-apitomcat-jsp-2.2-api 
tomcat6-libtomcat-lib 
totem-upnptotem 
udisksudisks2Not fully compatible.
un-core-batang-fontsnhn-nanum-myeongjo-fonts 
un-core-dinaru-fonts, un-core-graphic-fontsnhn-nanum-gothic-fontsNot fully compatible.
un-core-dotum-fontsnhn-nanum-gothic-fonts 
un-core-fonts-commonnhn-nanum-fonts-commonNot fully compatible.
un-core-gungseo-fontsnhn-nanum-brush-fontsNot fully compatible.
un-core-pilgi-fontsnhn-nanum-pen-fontsNot fully compatible.
uniqueunique3, glib2Not fully compatible.
unique-develunique3-develNot fully compatible.
unix2dosdos2unix 
vgabiosseavgabios-bin 
w3mtext-www-browserNot fully compatible.
xmlrpc3-*xmlrpc-* 
xorg-x11-drv-apmxorg-x11-drv-fbdev, xorg-x11-drv-vesa 
xorg-x11-drv-ast, xorg-x11-drv-cirrus, xorg-x11-drv-mgaxorg-x11-drv-modesetting 
xorg-x11-drv-ati-firmwarelinux-firmware 
xorg-x11-drv-elographics, xorg-x11-drv-glint, xorg-x11-drv-i128, xorg-x11-drv-i740, xorg-x11-drv-mach64, xorg-x11-drv-rendition, xorg-x11-drv-r128, xorg-x11-drv-savage, xorg-x11-drv-siliconmotion, xorg-x11-drv-sis, xorg-x11-drv-sisusb, xorg-x11-drv-s3virge, xorg-x11-drv-tdfx, xorg-x11-drv-trident, xorg-x11-drv-voodoo, xorg-x11-drv-xgixorg-x11-drv-fbdev, xorg-x11-drv-vesa 
xorg-x11-drv-nvxorg-x11-drv-nouveau 
xorg-x11-twmmetacityNot fully compatible.
xorg-x11-xdmgdmNot fully compatible.
yum-plugin-downloadonlyyum 

3.3. Deprecated Packages

The packages listed in this section are considered deprecated as of Red Hat Enterprise Linux 7. These packages still work, and remain supported, but Red Hat no longer recommends their use.

Table 3.2. Package deprecations

Functionality/Package
Alternative
Migration Notes
ext2 file system support
ext3, ext4
ext4 can be used for ext2 and ext3 file systems.
sblim-sfcb
tog-pegasus
 
Legacy RHN Hosted registration
subscription-manager and Subscription Asset Manager
 
acpid
systemd
 
evolution-mapi
evolution-ews
Please migrate from Microsoft Exchange Server 2003 machines
gtkhtml3
webkitgtk3
 
sendmail
postfix
 
edac-utils and mcelog
rasdaemon
 
libcgroup
systemd
cgutils will continue to exist in Red Hat Enterprise Linux 7.0 but systemd is evolving capabilities to enable customers to migrate in later releases
lvm1
lvm2
 
lvm2mirror and cmirror
lvm2 raid1
 

3.4. Removed Packages

The following packages have been removed from Red Hat Enterprise Linux between version 6 and version 7 and are no longer supported. Some of these packages may have functionally equivalent replacements available; see Section 3.2, “Package Replacements” for details.
  • amtu
  • ant-antlr
  • ant-apache-bcel
  • ant-apache-bsf
  • ant-apache-log4j
  • ant-apache-oro
  • ant-apache-regexp
  • ant-apache-resolver
  • ant-commons-logging
  • ant-commons-net
  • ant-javamail
  • ant-jdepend
  • ant-jsch
  • ant-junit
  • ant-nodeps
  • ant-swing
  • ant-trax
  • apache-jasper
  • apache-tomcat-apis
  • apr-util-ldap
  • arts
  • arts-devel
  • aspell
  • atmel-firmware
  • at-spi
  • at-spi-python
  • audiofile
  • audit-viewer
  • avahi-tools
  • avahi-ui
  • avalon-framework
  • avalon-logkit
  • batik
  • brasero
  • brasero-libs
  • brasero-nautilus
  • bsf
  • busybox
  • b43-fwcutter
  • b43-openfwwf
  • cas
  • cdparanoia
  • cdrdao
  • cjet
  • cloog-ppl
  • cluster-cim
  • cluster-glue
  • cluster-glue-libs
  • cluster-glue-libs-devel
  • clusterlib
  • clusterlib-devel
  • cluster-snmp
  • cman
  • compat-db42
  • compat-db43
  • compat-libstdc++-296
  • compat-libtermcap
  • compat-openmpi
  • compat-openmpi-psm
  • compat-opensm-libs
  • compiz
  • compiz-gnome
  • coreutils-libs
  • cracklib-python
  • cronie-noanacron
  • ctan-cm-lgc-fonts-common
  • ctan-cm-lgc-roman-fonts
  • ctan-cm-lgc-sans-fonts
  • ctan-cm-lgc-typewriter-fonts
  • ctan-kerkis-fonts-common
  • ctan-kerkis-sans-fonts
  • ctan-kerkis-serif-fonts
  • ctapi-common
  • cvs-inetd
  • c2050
  • c2070
  • dash
  • dbus-c++
  • dbus-qt
  • devhelp
  • dmz-cursor-themes
  • dtach
  • dvd+rw-tools
  • eclipse-birt
  • eclipse-callgraph
  • eclipse-cdt
  • eclipse-dtp
  • eclipse-emf
  • eclipse-gef
  • eclipse-changelog
  • eclipse-jdt
  • eclipse-linuxprofilingframework
  • eclipse-mylyn
  • eclipse-mylyn-cdt
  • eclipse-mylyn-java
  • eclipse-mylyn-pde
  • eclipse-mylyn-trac
  • eclipse-mylyn-webtasks
  • eclipse-mylyn-wikitext
  • eclipse-nls
  • eclipse-nls-ar
  • eclipse-nls-bg
  • eclipse-nls-ca
  • eclipse-nls-cs
  • eclipse-nls-da
  • eclipse-nls-de
  • eclipse-nls-el
  • eclipse-nls-es
  • eclipse-nls-et
  • eclipse-nls-fa
  • eclipse-nls-fi
  • eclipse-nls-fr
  • eclipse-nls-he
  • eclipse-nls-hi
  • eclipse-nls-hu
  • eclipse-nls-id
  • eclipse-nls-it
  • eclipse-nls-ja
  • eclipse-nls-ko
  • eclipse-nls-ku
  • eclipse-nls-mn
  • eclipse-nls-nl
  • eclipse-nls-no
  • eclipse-nls-pl
  • eclipse-nls-pt
  • eclipse-nls-pt_BR
  • eclipse-nls-ro
  • eclipse-nls-ru
  • eclipse-nls-sk
  • eclipse-nls-sl
  • eclipse-nls-sq
  • eclipse-nls-sr
  • eclipse-nls-sv
  • eclipse-nls-tr
  • eclipse-nls-uk
  • eclipse-nls-zh
  • eclipse-nls-zh_TW
  • eclipse-oprofile
  • eclipse-pde
  • eclipse-platform
  • eclipse-rcp
  • eclipse-rpm-editor
  • eclipse-rse
  • eclipse-subclipse
  • eclipse-subclipse-graph
  • eclipse-svnkit
  • eclipse-swt
  • eclipse-valgrind
  • ecryptfs-utils
  • evolution-data-server-doc
  • fakechroot
  • fakechroot-libs
  • fence-virt
  • fence-virtd-checkpoint
  • file-devel
  • firstaidkit
  • firstaidkit-engine
  • firstaidkit-gui
  • foghorn
  • fop
  • gamin-devel
  • gamin-python
  • gconfmm26
  • ggz-base-libs
  • glade3
  • gnome-disk-utility-libs
  • gnome-disk-utility-ui-libs
  • gnome-doc-utils
  • gnome-doc-utils-stylesheets
  • gnome-games
  • gnome-media
  • gnome-media-libs
  • gnome-pilot
  • gnome-pilot-conduits
  • gnome-power-manager
  • gnome-python2-bugbuddy
  • gnome-python2-extras
  • gnome-python2-gtkhtml2
  • gnome-python2-libegg
  • gnome-python2-libwnck
  • gnome-python2-rsvg
  • gnome-themes
  • gnome-user-share
  • gnome-vfs2-devel
  • gnome-vfs2-smb
  • graphviz-perl
  • groff
  • gsl-static
  • gstreamer-python
  • gthumb
  • gtk+extra
  • gtkhtml2
  • gtksourceview2
  • gtk2-engines
  • guile
  • gvfs-afc
  • gvfs-archive
  • hal-info
  • hal-libs
  • hal-storage-addon
  • htdig
  • hypervkvpd
  • ibus-table-additional
  • icedax
  • icu4j-eclipse
  • ipa-pki-ca-theme
  • ipa-pki-common-theme
  • ipw2100-firmware
  • ipw2200-firmware
  • jakarta-commons-discovery
  • jakarta-commons-el
  • jasper
  • java_cup
  • jdepend
  • jetty-eclipse
  • jsch
  • jzlib
  • kabi-yum-plugins
  • kcoloredit
  • kcoloredit-doc
  • kdeadmin
  • kdeartwork-screensavers
  • kdebase-workspace-akonadi
  • kdebase-workspace-python-applet
  • kdegames
  • kdegraphics
  • kde-i18n-Arabic
  • kde-i18n-Bengali
  • kde-i18n-Brazil
  • kde-i18n-British
  • kde-i18n-Bulgarian
  • kde-i18n-Catalan
  • kde-i18n-Czech
  • kde-i18n-Danish
  • kde-i18n-Dutch
  • kde-i18n-Estonian
  • kde-i18n-Finnish
  • kde-i18n-French
  • kde-i18n-German
  • kde-i18n-Greek
  • kde-i18n-Hebrew
  • kde-i18n-Hindi
  • kde-i18n-Hungarian
  • kde-i18n-Chinese
  • kde-i18n-Chinese-Big5
  • kde-i18n-Icelandic
  • kde-i18n-Italian
  • kde-i18n-Japanese
  • kde-i18n-Korean
  • kde-i18n-Lithuanian
  • kde-i18n-Norwegian
  • kde-i18n-Norwegian-Nynorsk
  • kde-i18n-Polish
  • kde-i18n-Portuguese
  • kde-i18n-Punjabi
  • kde-i18n-Romanian
  • kde-i18n-Russian
  • kde-i18n-Serbian
  • kde-i18n-Slovak
  • kde-i18n-Slovenian
  • kde-i18n-Spanish
  • kde-i18n-Swedish
  • kde-i18n-Tamil
  • kde-i18n-Turkish
  • kde-i18n-Ukrainian
  • kdelibs-apidocs
  • kdelibs3
  • kdelibs3-devel
  • kde-l10n-Bengali-India
  • kde-l10n-Frisian
  • kde-l10n-Gujarati
  • kde-l10n-Chhattisgarhi
  • kde-l10n-Kannada
  • kde-l10n-Kashubian
  • kde-l10n-Kurdish
  • kde-l10n-Macedonian
  • kde-l10n-Maithili
  • kde-l10n-Malayalam
  • kde-l10n-Marathi
  • kdemultimedia
  • kdemultimedia-devel
  • kdemultimedia-libs
  • kdenetwork
  • kdesdk
  • kdesdk-libs
  • kdeutils
  • kdewebdev
  • kdewebdev-libs
  • kernel-debug
  • kernel-debug-devel
  • kernel-doc
  • kiconedit
  • kipi-plugins
  • kipi-plugins-libs
  • kmid
  • kmid-common
  • konq-plugins-doc
  • krb5-appl
  • kross-python
  • ksig
  • ksig-doc
  • k3b
  • k3b-common
  • k3b-libs
  • libao-devel
  • libart_lgpl-devel
  • libbonobo-devel
  • libbonoboui-devel
  • libburn
  • libcroco-devel
  • libdc1394
  • libdiscid
  • libesmtp-devel
  • libexif-devel
  • libgail-gnome
  • libgcj
  • libgcj-devel
  • libgcj-src
  • libglademm24
  • libglade2-devel
  • libgnomecanvas-devel
  • libgnome-devel
  • libgnomeui-devel
  • libgphoto2-devel
  • libgpod
  • libgsf-devel
  • libgxim
  • libIDL-devel
  • libidn-devel
  • libisofs
  • libitm
  • libldb-devel
  • libmatchbox
  • libmtp
  • libmusicbrainz
  • libmusicbrainz3
  • libnih
  • liboil
  • libopenraw-gnome
  • libpanelappletmm
  • libproxy-bin
  • libproxy-python
  • libreport-compat
  • libreport-plugin-mailx
  • libreport-plugin-reportuploader
  • librtas (32-bit only)
  • libselinux-ruby
  • libservicelog (32-bit only)
  • libsexy
  • libtalloc-devel
  • libtdb-devel
  • libtevent-devel
  • libtidy
  • libvpd (32-bit only)
  • libwnck
  • libXdmcp-devel
  • log4cpp
  • lpg-java-compat
  • lucene
  • lucene-contrib
  • lx
  • lynx
  • MAKEDEV
  • matchbox-window-manager
  • mcstrans
  • mesa-dri1-drivers
  • min12xxw
  • mod_auth_mysql
  • mod_auth_pgsql
  • mod_authz_ldap
  • mod_dnssd
  • mrtg-libs
  • mvapich-psm-static
  • mx4j
  • nspluginwrapper
  • openct
  • openhpi-subagent
  • openssh-askpass
  • ORBit2-devel
  • osutil
  • oxygen-cursor-themes
  • PackageKit-yum-plugin
  • paktype-fonts-common
  • pam_passwdqc
  • pbm2l2030
  • pbm2l7k
  • pcmciautils
  • pcsc-lite-openct
  • perl-BSD-Resource
  • perl-Cache-Memcached
  • perl-Config-General
  • perl-Crypt-PasswdMD5
  • perl-Frontier-RPC
  • perl-Frontier-RPC-doc
  • perl-Perlilog
  • perl-String-CRC32
  • perl-suidperl
  • perl-Text-Iconv
  • perl-Time-HiRes
  • perl-YAML-Syck
  • pessulus
  • pilot-link
  • pinentry-gtk
  • piranha
  • pki-symkey
  • plpa-libs
  • plymouth-gdm-hooks
  • plymouth-theme-rings
  • plymouth-utils
  • policycoreutils-newrole
  • policycoreutils-sandbox
  • ppl
  • prelink
  • printer-filters
  • psutils
  • ptouch-driver
  • pulseaudio-module-gconf
  • pycairo-devel
  • pygobject2-codegen
  • pygobject2-devel
  • pygobject2-doc
  • pygtksourceview
  • pygtk2-codegen
  • pygtk2-devel
  • pygtk2-doc
  • pychart
  • PyOpenGL [1]
  • python-beaker
  • python-Coherence
  • python-crypto
  • python-decoratortools
  • python-enchant
  • python-formencode
  • python-fpconst
  • python-genshi
  • python-gtkextra
  • python-cheetah
  • python-ipaddr
  • python-iwlib
  • python-libguestfs [2]
  • python-louie
  • python-mako
  • python-markdown
  • python-markupsafe
  • python-matplotlib
  • python-myghty
  • python-paramiko
  • python-paste
  • python-paste-deploy
  • python-paste-script
  • python-peak-rules
  • python-peak-util-addons
  • python-peak-util-assembler
  • python-peak-util-extremes
  • python-peak-util-symbols
  • python-prioritized-methods
  • python-pygments
  • python-pylons
  • python-qpid
  • python-qpid-qmf
  • python-repoze-tm2
  • python-repoze-what
  • python-repoze-what-plugins-sql
  • python-repoze-what-pylons
  • python-repoze-what-quickstart
  • python-repoze-who
  • python-repoze-who-friendlyform
  • python-repoze-who-plugins-sa
  • python-repoze-who-testutil
  • python-routes
  • python-saslwrapper
  • python-sexy
  • python-sqlalchemy
  • python-tempita
  • python-toscawidgets
  • python-transaction
  • python-turbojson
  • python-tw-forms
  • python-twisted
  • python-twisted-conch
  • python-twisted-core
  • python-twisted-lore
  • python-twisted-mail
  • python-twisted-names
  • python-twisted-news
  • python-twisted-runner
  • python-twisted-web
  • python-twisted-words
  • python-weberror
  • python-webflash
  • python-webhelpers
  • python-webob
  • python-webtest
  • python-zope-filesystem
  • python-zope-interface
  • python-zope-sqlalchemy
  • pywebkitgtk
  • pyxf86config
  • qpid-cpp-client
  • qpid-cpp-client-ssl
  • qpid-cpp-server
  • qpid-cpp-server-ssl
  • qpid-qmf
  • qpid-tests
  • qpid-tools
  • qt-doc
  • raptor
  • rgmanager
  • rome
  • ruby-devel
  • ruby-qpid
  • ruby-qpid-qmf
  • sabayon
  • sabayon-apply
  • sac
  • samba-winbind-clients
  • samba4
  • samba4-client
  • samba4-common
  • samba4-dc
  • samba4-dc-libs
  • samba4-devel
  • samba4-pidl
  • samba4-swat
  • samba4-test
  • samba4-winbind
  • samba4-winbind-clients
  • samba4-winbind-krb5-locator
  • saslwrapper
  • sat4j
  • saxon
  • sblim-cmpi-dhcp
  • sblim-cmpi-dns
  • sblim-cmpi-samba
  • sblim-tools-libra
  • scenery-backgrounds
  • seabios
  • selinux-policy-minimum
  • selinux-policy-mls
  • setools-console
  • sgabios-bin
  • sigar
  • sinjdoc
  • smp_utils
  • SOAPpy
  • sound-juicer
  • strigi-devel
  • subscription-manager-migration-data
  • subversion-javahl
  • svnkit
  • system-config-firewall
  • system-config-firewall-tui
  • system-config-network-tui
  • system-config-services
  • system-config-services-docs
  • system-gnome-theme
  • system-icon-theme
  • taskjuggler
  • tbird
  • terminus-fonts
  • tidy
  • tigervnc-server
  • tix
  • tkinter
  • trilead-ssh2
  • tsclient
  • tunctl
  • TurboGears2
  • unicap
  • vorbis-tools
  • wacomexpresskeys
  • wdaemon
  • webalizer
  • webkitgtk
  • ws-commons-util
  • wsdl4j
  • xfig-plain
  • xfsprogs-devel
  • xfsprogs-qa-devel
  • xguest
  • xmldb-api
  • xmldb-api-sdk
  • xmlgraphics-commons
  • xorg-x11-apps
  • xorg-x11-drv-acecad
  • xorg-x11-drv-aiptek
  • xorg-x11-drv-fpit
  • xorg-x11-drv-hyperpen
  • xorg-x11-drv-keyboard
  • xorg-x11-drv-mouse
  • xorg-x11-drv-mutouch
  • xorg-x11-drv-openchrome
  • xorg-x11-drv-penmount
  • xorg-x11-server-Xephyr
  • xsane
  • xz-lzma-compat
  • zd1211-firmware

3.5. Removed Drivers

The following drivers have been removed from Red Hat Enterprise Linux between version 6 and version 7 and are no longer supported.
  • 3c574_cs.ko
  • 3c589_cs.ko
  • 3c59x.ko
  • 8390.ko
  • acenic.ko
  • amd8111e.ko
  • avma1_cs-ko [3]
  • avm_cs.ko[3]
  • axnet_cs.ko
  • b1pcmpcia.ko[3]
  • bluecard_cs-ko[3]
  • bt3c_cs.ko[3]
  • btuart_cs.ko[3]
  • can-dev.ko
  • cassini.ko
  • cdc-phonet.ko
  • cm4000_cs.ko[3]
  • cm4040_cs.ko[3]
  • cxgb.ko
  • de2104x.ko
  • de4x5.ko
  • dl2k.ko
  • dmfe.ko
  • dtl1_cs.ko[3]
  • e100.ko
  • elsa_cs.ko[3]
  • ems_pci.ko
  • ems_usb.ko
  • fealnx.ko
  • fmvj18x_cs.ko
  • forcedeth.ko
  • ipwireless.ko[3]
  • ixgb.ko
  • kvaser_pci.ko
  • myri10ge.ko
  • natsemi.ko
  • ne2k-pci.ko
  • niu.ko
  • nmclan_cs.ko
  • ns83820.ko
  • parport_cs.ko[3]
  • pata_pcmcia.ko[3]
  • pcnet_cs.ko
  • pcnet32.ko
  • pppol2tp.ko
  • r6040.ko
  • s2io.ko
  • sc92031.ko
  • sdricoh_cs.ko[3]
  • sedlbauer_cs.ko[3]
  • serial_cs.ko[3]
  • sis190.ko
  • sis900.ko
  • sja1000_platform.ko
  • sja1000.ko
  • smc91c92_cs.ko[3]
  • starfire.ko
  • sundance.ko
  • sungem_phy.ko
  • sungem.ko
  • sunhme.ko
  • tehuti.ko
  • teles_cs.ko[3]
  • tlan.ko
  • tulip.ko
  • typhoon.ko
  • uli526x.ko
  • vcan.ko
  • via-rhine.ko
  • via-velocity.ko
  • vxge.ko
  • winbond-840.ko
  • xirc2ps_cs.ko[3]
  • xircom_cb.ko

3.6. Deprecated Drivers

For information about deprecated drivers in Red Hat Enterprise Linux 7, see the most recent version of Release Notes on the Red Hat Customer Portal.


[1] Removed in Red Hat Enterprise Linux 7.0, replaced in Red Hat Enterprise Linux 7.1. Added to Optional channel in Red Hat Enterprise Linux 7.3. For more information about Optinal channel, see this solution article.
[2] Moved to the Optional repository for Red Hat Enterprise Linux 7.0, back in the base channel since Red Hat Enterprise Linux 7.1.
[3] The PCMCIA is not supported in Red Hat Enterprise Linux 7. It has been superseded by new technologies, including USB.

Appendix A. Customer Portal Labs Relevant For Migration

Red Hat Customer Portal Labs are tools designed to help you improve performance, troubleshoot issues, identify security problems, and optimize configuration. This appendix provides an overview of Red Hat Customer Portal Labs relevant to migration. All Red Hat Customer Portal Labs are available at http://access.redhat.com/labs/.

Red Hat Enterprise Linux Upgrade Helper

The Red Hat Enterprise Linux Update Helper is a tool that helps you upgrade your Red Hat Enterprise Linux from version 6.5/6.6/6.7/6.8/6.9 to version 7.x. The only information that you need to provide is your upgrade path. This application shows you:
  • the basic steps to upgrade Red Hat Enterprise Linux
  • extra steps that prevent known issues specific to your upgrade scenario
This application supports the following upgrade paths:
  • 6.5 to 7.4
  • 6.6 to 7.4
  • 6.7 to 7.4
  • 6.8 to 7.4
  • 6.9 to 7.4

Product Life Cycle Checker

The Product Life Cycle Checker is a tool for viewing Red Hat products' life-cycle information, including General Availability, End of Support, and End of Life. With this tool, it is possible to choose multiple products and view their dates.

Appendix B. Revision History

Note that revision numbers relate to the edition of this manual, not to version numbers of Red Hat Enterprise Linux.

Revision History
Revision 0.3-2Fri Apr 6 2018Lucie Maňásková
Preparing document for 7.5 GA publication.
Revision 0.3-1Fri Jul 28 2017Lucie Maňásková
Document version for 7.4 GA publication.
Revision 0.1-8Fri Sep 23 2016Lenka Špačková
Prepared the document for Red Hat Enterprise Linux 7.3 publication.
Revision 0.1-7Fri Sep 23 2016Lenka Špačková
Added the Deprecated Drivers section with a reference to Release Notes.
Revision 0.1-6Thu Nov 12 2015Mark Flitter
Prepared document for Red Hat Enterprise Linux 7.2 publication.
Revision 0.1-5Tue Feb 17 2015Laura Bailey
Prepared the document for Red Hat Enterprise Linux 7.1 publication.
Revision 0.1-4Mon Jun 02 2014Laura Bailey
Prepared the document for Red Hat Enterprise Linux 7.0 publication.
Revision 0.1-3Tue Mar 04 2014Laura Bailey
Importing transformed content for the first major draft post-Beta.
Revision 0.1-2Wed Jan 23 2013Scott Radvan
Design layout for new major version of guide.
Revision 0.1-1Wed Jan 16 2013Tahlia Richardson
Branched from the Red Hat Enterprise Linux 6 version of the document.

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