Bug 619334

Summary:	RFE: Enable coredump capture in the appliance
Product:	[Community] Virtualization Tools	Reporter:	Richard W.M. Jones <rjones>
Component:	libguestfs	Assignee:	Richard W.M. Jones <rjones>
Status:	ASSIGNED ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	low
Version:	unspecified	CC:	virt-maint
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:
Clones:	619345 (view as bug list)		Environment:
Last Closed:		Type:	---
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:	619345

Description Richard W.M. Jones 2010-07-29 10:04:41 UTC

Description of problem:

It should be possible to enable coredump capture in the appliance.  This
would allow us to more easily debug certain problems without requiring
'printf' statements as now.

It would work something like this:

(1) Add a handle variable called 'coredump' /
  LIBGUESTFS_COREDUMP=<path>

(2) This sets a kernel parameter for the appliance.

(3) If the kernel parameter is set then the daemon enables coredumps:

  (a) echo /sysroot/<path>/core.%t.%e > /proc/sys/kernel/core_pattern
  (b) Set ulimit core unlimited

(4) After something coredumps (even the daemon) this ought to
  capture the coredump on the currently mounted device.

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

1.5.x

Comment 1 Richard W.M. Jones 2010-07-29 10:05:35 UTC

I wonder if we can coredump to a raw disk?  Then the user could
add a "coredump capture disk".

Comment 2 Matthew Booth 2010-07-29 10:15:30 UTC

Unless we plan to turn this on by default, this is really a developer tool. I think we can assume to a significant extent that the user understands exactly how it works and what the implications of using it are. This would include, for example, choosing a sensible value for LIBGUESTFS_COREDUMP for the current image file. I'd keep this one simple.

Comment 3 Richard W.M. Jones 2010-07-31 16:21:24 UTC

Patch posted upstream:
https://www.redhat.com/archives/libguestfs/2010-July/msg00090.html

Comment 4 Richard W.M. Jones 2011-07-14 19:14:21 UTC

Setting back to ASSIGNED.  The patch was not acceptable
upstream.  This requires a fix to the kernel, which the
kernel developers have rejected.