Public bug reported: == Comment: #0 - Hari Krishna Bathini <[email protected]> - 2018-06-26 00:47:43 == ---Problem Description--- Since kernel commit 11550dc0a00b ("powerpc/fadump: reuse crashkernel parameter for fadump memory reservation"), crashkernel parameter is used to reserve memory for fadump, as well. Machine Type = na ---Steps to Reproduce--- Install a Ubuntu kernel that is based on kernel v4.12 or above, and use crashkernel instead of fadump_reserve_mem to specify the memory to be reserved for fadump ---uname output--- na ---Debugger--- A debugger is not configured Contact Information = [email protected]
== Comment: #2 - Hari Krishna Bathini <[email protected]> - 2018-06-26 01:16:50 == The section *Firmware Assisted Dump* in https://wiki.ubuntu.com/ppc64el/Recommendations should not be listed under *Bare Metal* as fadump is not specific to bare-metal. In fact, it is NOT supported on bare-metal currently., Please remove *Bare Metal* as section heading and update the section to look like the below: --- *Firmware Assisted Dump* Firmware Assisted Dump (fadump) is an alternative to kdump crash dumping mechanism, available in powerpc architecture. To understand how fadump works, please refer to the kernel documentation below: https://www.kernel.org/doc/Documentation/powerpc/firmware-assisted- dump.txt Three steps are needed to use fadump as the crash dumping mechanism. Firstly, enabling fadump by passing "fadump=on" to kernel. Secondly, reserving some memory for fadump. Thirdly, registering fadump by echo'ing 1 to /sys/kernel/fadump_registered. 1. To enable fadump: Add "fadump=on" to GRUB_CMDLINE_LINUX in /etc/default/grub file. Rebuild grub config # grub-mkconfig -o /boot/grub/grub.cfg 2. To reserve memory for fadump: Add "fadump_reserve_mem=<mem>" to GRUB_CMDLINE_LINUX in /etc/default/grub file. Rebuild grub config # grub-mkconfig -o /boot/grub/grub.cfg NOTE: For ubuntu kernel that is based on kernel v4.12 or above, use 'crashkernel=' instead of 'fadump_reserve_mem=', to specify the memory to be reserved for fadump 3. To register fadump: Reboot the system for steps 1 & 2 to take effect. kdump-tools, scripts and tools for automating kdump, is updated to make it fadump aware. When fadump is enabled, kdump-tools registers fadump as crash dumping mechanism, by echo'ing 1 to /sys/kernel/fadump_registered. For more help, see: # kdump-config help NOTE: If fadump fails to collect dump with Out Of Memory error, spike up the memory reserved for firmware-assisted dump (See step2). --- Thanks Hari ** Affects: ubuntu-docs (Ubuntu) Importance: Undecided Assignee: Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage) Status: New ** Tags: architecture-ppc64le bugnameltc-169217 severity-high targetmilestone-inin--- ** Tags added: architecture-ppc64le bugnameltc-169217 severity-high targetmilestone-inin--- ** Changed in: ubuntu Assignee: (unassigned) => Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage) ** Package changed: ubuntu => ubuntu-docs (Ubuntu) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1778651 Title: Update documentation about crashkernel parameter reuse for fadump To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-docs/+bug/1778651/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
