Chapter 5. Known Issues

Physical-extents size less than 32MB on top of an MD physical volume leads to problems with calculating the capacity of a volume group. To work around this problem, use a physical-extent size of 32MB or leave space double the physical-extent size free when allocating logical volumes. Another option is to change the default 4MB size of a physical extent to 32MB.

After upgrading the system using kickstart, IBM System z machines halt instead of rebooting, despite the instruction to reboot. To work around this problem, boot the system manually.

Setting the qla4xxx parameter ql4xdisablesysfsboot to 1 may cause boot from SAN failures.

To automatically create an appropriate partition table on disks that are uninitialized or contain unrecognized formatting, use the zerombr kickstart command. The --initlabel option of the clearpart command is not intended to serve this purpose.

Users performing an upgrade using the Anaconda's text mode interface who do not have a boot loader already installed on the system, or who have a non-GRUB boot loader, need to select Skip Boot Loader Configuration during the installation process. Boot loader configuration will need to be completed manually after installation. This problem does not affect users running Anaconda in the graphical mode (graphical mode also includes VNC connectivity mode).

On s390x systems, you cannot use automatic partitioning and encryption. If you want to use storage encryption, you must perform custom partitioning. Do not place the /boot volume on an encrypted volume.

The order of device names assigned to USB attached storage devices is not guaranteed. Certain USB attached storage devices may take longer to initialize than others, which can result in the device receiving a different name than you expect (for example, sdc instead of sda).

During installation, verify the storage device size, name, and type when configuring partitions and file systems.

Recent Red Hat Enterprise Linux 6 releases use a new naming scheme for network interfaces on some machines. As a result, the installer may use different names during an upgrade in certain scenarios (typically em1 is used instead of eth0 on new Dell machines). However, the previously used network interface names are preserved on the system and the upgraded system will still use the previously used interfaces. This is not the case for Yum upgrades.

The kdump default on feature currently depends on Anaconda to insert the crashkernel= parameter to the kernel parameter list in the boot loader's configuration file.

The firstaidkit-plugin-grub package has been removed from Red Hat Enterprise Linux 6.2. As a consequence, in rare cases, the system upgrade operation may fail with unresolved dependencies if the plug-in has been installed in a previous version of Red Hat Enterprise Linux. To avoid this problem, the firstaidkit-plugin-grub package should be removed before upgrading the system. However, in most cases, the system upgrade completes as expected.

In some circumstances, disks that contain a whole disk format (for example, an LVM Physical Volume populating a whole disk) are not cleared correctly using the clearpart --initlabel kickstart command. Adding the --all switch—as in clearpart --initlabel --all—ensures disks are cleared correctly.

When installing on the IBM System z architecture, if the installation is being performed over SSH, avoid resizing the terminal window containing the SSH session. If the terminal window is resized during the installation, the installer will exit and the installation will terminate.

The kernel image provided on the CD/DVD is too large for Open Firmware. Consequently, on the POWER architecture, directly booting the kernel image over a network from the CD/DVD is not possible. Instead, use yaboot to boot from a network.

The Anaconda partition editing interface includes a button labeled Resize. This feature is intended for users wishing to shrink an existing file system and an underlying volume to make room for an installation of a new system. Users performing manual partitioning cannot use the Resize button to change sizes of partitions as they create them. If you determine a partition needs to be larger than you initially created it, you must delete the first one in the partitioning editor and create a new one with the larger size.

Channel IDs (read, write, data) for network devices are required for defining and configuring network devices on IBM S/390 systems. However, system-config-kickstart—the graphical user interface for generating a kickstart configuration—cannot define channel IDs for a network device. To work around this issue, manually edit the kickstart configuration that system-config-kickstart generates to include the desired network devices.