Update documentation about crashkernel parameter reuse for fadump
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
The Ubuntu-power-systems project |
Fix Released
|
High
|
Manoj Iyer | ||
Ubuntu |
Fix Released
|
Undecided
|
Ubuntu on IBM Power Systems Bug Triage |
Bug Description
== Comment: #0 - Hari Krishna Bathini <email address hidden> - 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 address hidden>
== Comment: #2 - Hari Krishna Bathini <email address hidden> - 2018-06-26 01:16:50 ==
The section *Firmware Assisted Dump* in
https:/
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:/
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/
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_
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_
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/
# 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
tags: | added: architecture-ppc64le bugnameltc-169217 severity-high targetmilestone-inin--- |
Changed in ubuntu: | |
assignee: | nobody → Ubuntu on IBM Power Systems Bug Triage (ubuntu-power-triage) |
affects: | ubuntu → ubuntu-docs (Ubuntu) |
Changed in ubuntu-power-systems: | |
importance: | Undecided → High |
tags: | added: triage-g |
Changed in ubuntu-power-systems: | |
assignee: | nobody → Manoj Iyer (manjo) |
tags: |
added: targetmilestone-inin16044 removed: targetmilestone-inin--- |
The ubuntu-docs package installs part of the Ubuntu Desktop Guide, and is unrelated to this issue. Changing to generic Ubuntu for now.