Red Hat Bugzilla – Bug 605732
service kdump start fails even though there is memory reserved for the crashkernel
Last modified: 2010-11-10 16:00:20 EST
Description of problem:
On one of my systems, service kdump start fails, with no reason given. /var/log/messages just shows that the kexec kernel failed to load:
Jun 18 12:04:02 metallica kdump: kexec: failed to load kdump kernel
Jun 18 12:04:02 metallica kdump: failed to start up
The crashkernel has memory reserved:
[root@metallica ~]# cat /proc/iomem
00000000-00000fff : reserved
00001000-0009fbff : System RAM
0009fc00-0009ffff : reserved
000f0000-000fffff : reserved
00100000-d7e65fff : System RAM
01000000-0150faf4 : Kernel code
0150faf5-0192122f : Kernel data
01c28000-028c3717 : Kernel bss
04000000-0bffffff : Crash kernel
[root@metallica ~]# cat /proc/cmdline
ro root=UUID=fcd9cac9-0500-4c87-b1e0-f992ee94c289 console=ttyS1 crashkernel=128M@64M elevator=deadline SYSFONT=latarcyrheb-sun16 LANG=en_US.UTF-8 KEYTABLE=us
Version-Release number of selected component (if applicable):
Steps to Reproduce:
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Hat Enterprise Linux major release. Product Management has requested further
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I"ve spoken and tested with jeff on this, and this appears limited to the debug kernels. I think whats happening is that the debug kernels have a different START_KERNEL vaddr than the non-debug kernels, and kdump doesn't know about that, so it fails in get_kernel_vaddr_and_size. I'll investigate and put a patch together soon.
*** Bug 608476 has been marked as a duplicate of this bug. ***
This issue has been proposed when we are only considering blocker
issues in the current Red Hat Enterprise Linux release. It has
been denied for the current Red Hat Enterprise Linux release.
** If you would still like this issue considered for the current
release, ask your support representative to file as a blocker on
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Jeff, I think I was close, but not quite spot on with my assumption in comment 3. Its not the kernel start address that we're failing to find, but the comparison on its end address. The kernel can be up to 512Mb in size, but kexec thinks it can only be 40Mb. I'm guessing that the debug kernel fails the KERNEL_TEXT_SIZE check. I've updated it the patch I'm going to attach shortly. If you could try this build:
Which has the patch attached and confirm it solves the problem here, that would be great. Thanks!
Created attachment 432139 [details]
patch to correctly limit kernel text size
This is working for me.
This works for me. Thanks!
Red Hat Enterprise Linux 6.0 is now available and should resolve
the problem described in this bug report. This report is therefore being closed
with a resolution of CURRENTRELEASE. You may reopen this bug report if the
solution does not work for you.