Bug 1359031

Summary:	[Document] debug kernel dump explain
Product:	Red Hat Enterprise Linux 7	Reporter:	Qiao Zhao <qzhao>
Component:	kexec-tools	Assignee:	Bhupesh Sharma <bhsharma>
Status:	CLOSED ERRATA	QA Contact:	Emma Wu <xiawu>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.3	CC:	bhsharma, piliu, ruyang
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	kexec-tools-2.0.14-5.el7	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-08-01 09:31:21 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1394638, 1404314

Description Qiao Zhao 2016-07-22 06:55:08 UTC

Description of problem:
QE found some error/panic on 2nd kernel, like bug:
https://bugzilla.redhat.com/show_bug.cgi?id=1352430
https://bugzilla.redhat.com/show_bug.cgi?id=1266622

I have talked with Dave Young, he said, "crashkernel=auto does not
support debug kernel because a lot of debug options been enabled."
I think we should announce this in our kexec-kdump-howto.txt file,
if anyone want to use kdump on debug kernel.

Version-Release number of selected component (if applicable):


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Comment 1 Qiao Zhao 2016-11-16 03:08:26 UTC

Now is 7.4, add 7.4.0 flag.

Comment 2 Bhupesh Sharma 2017-04-05 06:22:41 UTC

As discussed with Dave and Bao on IRC, the debug kernels cannot be reliably used as crash/kdump kernels when the crash kernel memory is setup using the 'crashkernel=auto' boot argument.

This is because the debug kernels might enable a number of features which might cause the memory used by the same to swell up, which cannot be reliably met by using 'crashkernel=auto' boot argument.

Will cook up a patch to mention this limitation in kexec-kdump-howto.txt file.

Comment 7 errata-xmlrpc 2017-08-01 09:31:21 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2017:2300