Kernel panic can occur when KDUMP_IMMEDIATE_REBOOT is set to "no"

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Environment

SUSE Linux Enterprise Server 11 Service Pack 4 (SLES 11 SP4)

Situation

On SLE11 SP4 set KDUMP_IMMEDIATE_REBOOT="no" in /etc/sysconfig/kdump.

Trigger a crash. (echo "c" > /proc/sysrq-trigger)

The system prints the following message: "Type 'reboot -f' to reboot the system or 'exit' to boot in a normal system that still is running in the kdump environment with restricted memory!"

The system opens a shell after performing kernel dump waiting for user input. If "exit" is typed at the prompt, the system will panic.

Resolution

Possible workarounds include:

- do not use KDUMP_IMMEDIATE_REBOOT="no"

- run "umount /kdump/root" before exiting the shell started with KDUMP_IMMEDIATE_REBOOT="no"

- run "reboot -f"

Cause

This issue is caused by a leftover mount on /kdump/root. The system panics after exiting the shell instead of continuing normal boot.

Disclaimer

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