Initiating a dump

A kernel panic automatically triggers the dump process with kdump. If this automation fails, there are other methods you can use to trigger the dump process.

About this task

With kdump installed, a kernel panic or PSW restart trigger kdump rather than the shutdown actions defined in /sys/firmware. The definitions in /sys/firmware are used only if an integrity check for kdump fails (see also Failure recovery and backup tools and dumpconf - Configure panic or PSW restart action).

To trigger kdump, use one of the methods according to your environment:

  • 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.
Tip: Start of changeOn both z/VM and LPAR you can use the diag288 watchdog to trigger kdump. The default setup triggers the correct actions. For more details about the diag288 watchdog, see Device Drivers, Features, and Commands on SUSE Linux Enterprise Server 12 SP3, SC34-2745End of change
  • z/VM guest example
    With kdump you do not need a dump device to initiate the dump.
  • LPAR example
    You can initiate a kdump process on an LPAR from an HMC (Hardware Management Console) or SE (Support Element).
  • z/VM guest example
    With kdump you do not need a dump device to initiate the dump.
  • LPAR example
    You can initiate a kdump process on an LPAR from an HMC (Hardware Management Console) or SE (Support Element).
Start of change

Results

After kdump is triggered, first kernel messages from the booting kdump kernel and later dump progress messages are issued. The messages are written to the Operating System Messages applet of the HMC for LPAR and to the 3270 terminal for z/VM. The kdump scripts copy the dump and reboot automatically. End of change

What to do next

Verify that your production system is up and running again. Send the created dump to your support organization.
Parent topic: Using kdump
Previous topic: Setting up kdump