2.2. Installation and Boot
2.2.1. New Boot Loader
Table 2.1. Recommended minimum partition sizes
|Partition||BIOS & MBR||BIOS & GPT||UEFI & GPT|
|swap||At least twice the RAM. See Section 18.104.22.168. Recommended Partitioning Scheme in the Red Hat Enterprise Linux 7 Installation Guide for details.|
|boot loader||N/A (Installed between the partition table and the first partition)||1 MB (BIOS Boot Partition)||200 MB (EFI System Partition|
forceoption 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/.
# grub2-mkconfig -o /boot/grub2/grub.cfg
# grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg
22.214.171.124. Default Boot Entry for Debugging
/etc/grub.cfgfile. 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
126.96.36.199. Backwards Compatibility
status) still work. However, Red Hat recommends
/usr/sbin/service servicenamecommands, as they forward directly to
systemdrather 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.targetsystemd 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
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
- SysV services, even those with root privileges, cannot acquire real-time scheduling when the
CPUAccountingoption is enabled. With
CPUAccountingenabled 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_usoption 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.
- 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.
- 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.
- If this option is specified, the
debug-shell.serviceis 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
188.8.131.52. New Installer
- 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
realmdD-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.
- 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.repoparameter to set network and other install locations instead of using the
- 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.
184.108.40.206. Boot parameter changes
220.127.116.11.1. Specifying boot parameters
inst.in this guide. Currently, this prefix is optional in Red Hat Enterprise Linux 7:
resolution=1024x768works 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.
18.104.22.168.2. Changes to boot parameters
22.214.171.124.2.1. New parameters
- Specifies the location of the installation program runtime image to be loaded. The syntax is the same as the syntax of the
inst.repoparameter. This option ignores everything but the image; it cannot be used to specify the location of packages.
- 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
- 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 valuesValueEffect0Disables geolocation.provider_fedora_geoipUses the Fedora GeoIP API.provider_hostipUses the Hostip.info GeoIP API.
- Specifies that the frame buffer X driver should be used instead of a hardware specific driver. This option is equivalent to
- Specifies the boot interface. This option is mandatory if
ipis specified more than once.
- Configures the system for multilib packages, for example, to allow 32-bit packages to be installed on a 64-bit system.
- Installs partition information into a GUID Partition Table (GPT) instead of the Master Boot Record (MBR).
- 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.
- Takes a Direct Access Storage Device (DASD) adaptor device bus identifier and, optionally, comma separated
sysfsparameter and value pairs. Activates the DASD with the specified device bus ID and sets the mentioned
sysfsparameters to the values specified. For example,
rd.dasd=adaptor_id,readonly=0. This parameter can be specified multiple times to activate multiple DASDs.
- 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.
- Takes a network protocol type, a comma delimited list of subchannels, and, optionally, comma delimited
sysfsparameter 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.
126.96.36.199.2.2. Changed parameters
kssendmac. Adds headers to outgoing HTTP requests including the MAC addresses of all network interfaces. This is useful when using
inst.ks=httpto provision systems.
- name server
dns. Specifies the address of the name server. This option can be used multiple times.
188.8.131.52.2.3. Deprecated parameters
- Specified the location of updates for the installation program. Use the
- Configured the installation method. Use the
- 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
- Configured the Domain Name Server (DNS). Use the
- netmask, gateway, hostname, ip, ipv6
- These options have been consolidated under the
- Specified the
BOOTIFoption used when installing from a PXE server. This is now detected automatically.
- 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 valuesValueCurrent behaviorNot presentAttempt to activate all devices with DHCP, unless a device and configuration are specified with the
BOOTIFoptions.ksdevice=linkIgnored (this is the same as the default behavior).ksdevice=bootifIgnored (
BOOTIFis used as the default if specified).ksdevice=ibftReplaced with dracut option
BOOTIF=MAC.ksdevice=deviceReplaced with device specification in the dracut
- Used to disable specified drivers. This is now handled by the
rd.driver.blacklistdracut option with the following syntax:
- Disabled support for the FireWire interface. You can disable the FireWire driver (
firewire_ohci) by using the
184.108.40.206.2.4. Removed parameters
- This option forced Anaconda to use the
/dev/ttyS0console as the output. Use the
consoleparameter to specify the
/dev/ttyS0console (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.
- Used in the past to configure additional low-level network settings. All network settings are now handled by the
- Allowed you to debug the loader. Use
- Verified the installation media before starting the installation. Replaced with the
- Specified a diskette as the Kickstart file source. Floppy drives are no longer a supported boot medium.
- Configured a remote display. Replaced with the
- Added UTF8 support when installing in text mode. UTF8 support now works automatically.
- 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
- Configured a VLAN device. Replaced with the dracut
2.2.3. Changes to firstboot Implementation
2.2.4. Changed mount behavior at boot
/etc/fstabcould be mounted. This could result in a system appearing "up" and healthy, while booting without required partitions.
/etc/fstabcannot 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
/dev/critical /critical xfs defaults 1 2 /dev/optional /optional xfs defaults,nofail 1 2
/optionalwould not cause boot to fail if it could not be mounted successfully.
2.2.5. Changes to /etc/issue file
/etc/issuefile 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-releasefile and the first line of
/etc/issuenow contains an agetty escape code
\Sescape code expands in the console displaying a product name and the release number of the machine. The code is represented by the
PRETTY_NAMEvariable, which is defined in the
\Sescape code works only from the console. Using the expansion in an environment that does not support it will result in printing only "\S".
\S, see the agetty man pages.