When booting LPARs with large amounts of CPU and memory assigned, the system may time-out and stop in “emergency mode”.

Content

Linux Releases Affected
SUSE Linux Enterprise Server 12, Service Pack 3

SUSE Linux Enterprise Server 15

IBM Systems Affected
All systems

Symptoms
When booting logical partitions with large amounts of CPU and memory assigned, the system may time-out and stop in “emergency mode”, showing messages similar to these:

You are in emergency mode. After logging in, type "journalctl -xb" to view
system logs, "systemctl reboot" to reboot, "systemctl default" or ^D to
try again to boot into default mode.
Give root password for maintenance
(or press Control-D to continue):

The system should show messages prior to this that complain of a timeout waiting for devices, specifically the device for the /home filesystem. This issue has been seen in configurations with a very large number of CPUs and a large amount of memory assigned to the LPAR.

Workaround
The system can usually be booted simply by entering the root password and pressing Ctrl-D or typing “exit” at the shell prompt. In some cases, it may be necessary to enter the command “lvm lvchange -a y system” before exiting the emergency mode shell.

A more-permanent workaround is to edit the file /etc/default/grub. In this file, append “systemd.default_timeout_start_sec=1800” to the GRUB_CMDLINE_LINUX_DEFAULT entry. After making this change, run “grub2-mkconfig -o /boot/grub2/grub.cfg” to update the bootloader configuration.

Fix Outlook
IBM is working closely with SuSE to release a fix for this issue. The fix should come as part of a future SLES maintenance release.

SUSE Bugzilla 1103094.