Initiating a dump
A kernel panic automatically triggers the dump process with kdump. When your Linux® system does not respond and kdump is not triggered automatically, depending on your system environment, there are additional methods for triggering the dump process.
About this task
To trigger kdump, use one of the methods according to your environment:
- For Linux on KVM: Issue the virsh inject-nmi command on the KVM host.
- For Linux on z/VM®: Run the z/VM CP system restart command.
- For Linux in LPAR mode: Run the PSW restart task on the HMC.
In all three environments, you can use the
following methods to trigger a dump.
- The diag288 watchdog
- You can use the diag288 watchdog to trigger kdump. The default setup triggers the correct actions.
- The magic sysrequest feature
- Crash the kernel through the magic sysrequest feature, for example by writing c to
/proc/sysrq-trigger.
# echo c > /proc/sysrq-trigger
Hint: You might have to write 1 to /proc/sys/kernel/sysrq first to enable the sysrequest feature.