Red Hat Training

A Red Hat training course is available for Red Hat Enterprise Linux

Chapter 17. Servers and Services

rear rebased to version 2.4

The rear packages that provide the Relax-and-Recover tool (ReaR) have been upgraded to upstream version 2.4, which provides a number of bug fixes and enhancements over the previous version. Notably:
  • The default behavior when resizing partitions in migration mode has been changed. Only the size of the last partition is now changed by default; the start positions of every partition are preserved. If the previous behavior is needed, set the AUTORESIZE_PARTITIONS configuration variable to yes. See the description of the configuration variables AUTORESIZE_PARTITIONS, AUTORESIZE_EXCLUDE_PARTITIONS, AUTOSHRINK_DISK_SIZE_LIMIT_PERCENTAGE, and AUTOINCREASE_DISK_SIZE_THRESHOLD_PERCENTAGE in the /usr/share/rear/conf/default.conf file for more information on how to control the partition resizing.
  • The network setup now supports teaming (with the exception of Link Aggregation Control Protocol - LACP), bridges, bonding, and VLANs.
  • Support for Tivoli Storage Manager (TSM) has been improved. In particular, support for the password store in the TSM client versions 8.1.2 and later has been added, fixing the bug where the generated ISO image did not support restoring the OS if those TSM versions were used for backup.
  • Support for partition names containing blank and slash characters has been fixed.
  • SSH secrets (private keys) are no longer copied to the recovery system, which prevents their leaking. As a consequence, SSH in the recovery system cannot use the secret keys from the original system. See the description of the SSH_FILES, SSH_ROOT_PASSWORD, and SSH_UNPROTECTED_PRIVATE_KEYS variables in the /usr/share/rear/conf/default.conf file for more information on controlling this behavior.
  • Numerous improvements to support of the IBM POWER Systems architecture have been added, such as support for including the backup in the rescue ISO image and for multiple ISOs.
  • Multipath support has been enhanced. For example, support for software RAID on multipath devices has been added.
  • Support for secure boot has been added. The SECURE_BOOT_BOOTLOADER variable can be used for specifying any custom-signed boot loader.
  • Support for restoring disk layout of software RAID devices with missing components has been added.
  • The standard error and standard output channels of programs invoked by ReaR are redirected to the log file instead of appearing on the terminal. Programs prompting for user input on the standard output or standard error channel will not work correctly. Their standard output channel should be redirected to file descriptor 7 and standard input channel from file descriptor 6. See the Coding Style documentation on the ReaR wiki for more details.
  • Support for recovery of systems with LVM thin pool and thin volumes has been added. (BZ#1496518, BZ#1484051, BZ#1534646, BZ#1498828, BZ#1571266, BZ#1539063, BZ#1464353, BZ#1536023)

The rear package now includes a user guide

This update adds the user guide into the rear package, which provides the Relax-and-Recover tool (ReaR). After installation of rear, you can find the user guide in the /usr/share/doc/rear-2.4/relax-and-recover-user-guide.html file. (BZ#1418459)

The pcsc-lite interface now supports up to 32 devices

In Red Hat Enterprise Linux 7.6, the number of devices the pcsc-lite smart card interface supports has been increased from 16 to 32. (BZ#1516993)

tuned rebased to version 2.10.0

The tuned packages have been rebased to upstream version 2.10.0, which provides a number of bug fixes and enhancements over the previous version.
Notable changes include:
  • an added mssql profile (shipped in a separate tuned-profiles-mssql subpackage)
  • the tuned-adm tool now displays a relevant log snippet in case of error
  • fixed verification of a CPU mask on systems with more than 32 cores (BZ#1546598)

The STOU FTP command has improved algorithm for generating unique file names

The STOU FTP command allows transferring files to the server and storing them with unique file names. Previously, the STOU command created the names of the files by taking the file name, supplied as an argument to the command, and adding a numerical suffix and incrementing the suffix by one. In some cases, this led to a race condition. Subsequently the scripts which used STOU to upload files with the same file name could fail. This update modifies STOU to create unique file names in a way which helps to avoid the race condition and improves the functioning of scripts that use STOU. To enable the improved algorithm for generating unique file names using STOU, enable the better_stou option in the configuration file (usually /etc/vsftpd/vsftpd.conf) by adding the following line:
better_stou=YES (BZ#1479237)

rsyslog imfile now supports symlinks

With this update, the rsyslog imfile module delivers better performance and more configuration options. This enables to use the module for more complicated file monitoring use cases. Users of rsyslog are now able to use file monitors with glob patterns anywhere along the configured path and rotate symlink targets with increased data throughput when compared to the previous version. (BZ#1531295)

New rsyslog module: omkafka

To enable kafka centralized data storage scenarios, you can now forward logs to the kafka infrastructure using the new omkafka module. (BZ#1482819)

New rsyslog module: mmkubernetes

To enable scenarios using rsyslog in favor of other log collectors and where kubernetes container metadata are required, a new mmkubernetes module has been added to Red Hat Enterprise Linux. (BZ#1539193)