crashkernel memory reservation ignored

[Jamin W. Collins]

In attempting to track down a rather elusive kernel panic I've begun trying to use the kdump facility based on information found here (https://wiki.ubuntu.com/KernelTeam/CrashdumpRecipe). However, attempting to execute the kexec command results in an error that the crashkernel memory has not been reserved. Near as I can tell, the kernel parameters are correct.

# grep 'Command line:' /var/log/dmesg
[ 0.000000] Command line: root=UUID=66cf90ad-d4ec-4ec1-afb0-3fc3b17e3141 ro vga=0x37d quiet splash crashkernel=384M-2G:64M@16M,2G-:128M@16M

# uname -r
2.6.28-11-generic

# kexec -p /boot/vmlinuz-2.6.28-11-generic --initrd=/boot/initrd.img-2.6.28-11-generic --append=root=UUID=66cf90ad-d4ec-4ec1-afb0-3fc3b17e3141 irqpoll maxcpus=1
Memory for crashkernel is not reserved
Please reserve memory by passing "crashkernel=X@Y" parameter to the kernel
Then try loading kdump kernel

ProblemType: Bug
Architecture: amd64
DistroRelease: Ubuntu 9.04
MachineType: LENOVO
NonfreeKernelModules: nvidia ath_hal
Package: linux-image-2.6.28-11-generic 2.6.28-11.42
ProcCmdLine: root=UUID=66cf90ad-d4ec-4ec1-afb0-3fc3b17e3141 ro vga=0x37d quiet splash crashkernel=384M-2G:64M@16M,2G-:128M@16M
ProcEnviron:
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcVersionSignature: Ubuntu 2.6.28-11.42-generic
SourcePackage: linux

[Irfan Adilovic (irfy)]

I am observing the exact same behavior. Same crashkernel argument, same kernel, same arch, same distro, also nvidia nonfree kernel module.

[Stanislaw Pitucha (viraptor-gmail)]

Same here. Is there any specific data I should report?

[Kings (kingslee)]

I get such message "Memory for crashkernel is not reserved" everytime I boot.

kernel argument ro vga=795 crashkernel=384M-2G:64M@16M,2G-:128M@16M, also nvidia nonfree kernel module, using "server" "Linux server1 2.6.28-11-server #42-Ubuntu SMP Fri Apr 17 02:45:36 UTC 2009 x86_64 GNU/Linux" kernel

[phirestalker (firestalker1-deactivatedaccount)]

me too
root=UUID=66252ae1-96e2-4f6b-bfd3-f8194579fa34 ro splash crashkernel=384M-2G:64M@16M,2G-:128M@16M

[phirestalker (firestalker1-deactivatedaccount)]

oh but I don't have any proprietary drivers installed

[Duane Waddle (duane-waddle)]

I've seen the same thing on my x86 Jaunty - updating the grub menu.lst to where the argument for crashkernel is just "crashkernel=128M" seems to fix the reservation problem.

[Andy Whitcroft (apw)]

On my current setup this is using the following incantion, note that it does not specify the location, can you see if that helps:

    crashkernel=384M-2G:64M,2G-:128M

[Duane Waddle (duane-waddle)]

Andy's suggestion of "crashkernel=384M-2G:64M,2G-:128M" gets me a proper reservation on 2.6.28-15-generic.

Sep 17 16:21:03 localhost kernel: [ 0.000000] Reserving 128MB of memory at 32MB for crashkernel (System RAM: 3062MB)

[Jamin W. Collins (jcollins)]

Looks like Lucid gets the reservation correct (crashkernel=384M-2G:64M,2G-:128M) as I see the following:

[ 0.000000] Reserving 128MB of memory at 32MB for crashkernel (System RAM: 9152MB)

Additionally, my system has now been generating crash dumps (and rebooting) instead of simply freezing.