Bug 817776

Summary:	Improve resilience & robustness of lvmetad
Product:	Red Hat Enterprise Linux 6	Reporter:	Alasdair Kergon <agk>
Component:	lvm2	Assignee:	Petr Rockai <prockai>
Status:	CLOSED NEXTRELEASE	QA Contact:	Cluster QE <mspqa-list>
Severity:	medium	Docs Contact:
Priority:	high
Version:	6.4	CC:	agk, cmarthal, dwysocha, heinzm, jbrassow, msnitzer, prajnoha, prockai, syeghiay, thornber, zkabelac
Target Milestone:	pre-dev-freeze	Keywords:	Tracking
Target Release:	6.4
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2012-11-19 15:56:39 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:	813766, 814782, 823660, 823667, 823918
Bug Blocks:

Description Alasdair Kergon 2012-05-01 08:41:02 UTC

Consider all failure modes and improve/document handling wherever possible.

Ensure all relevant internal state is easily available in support situations e.g. via lvmdump.

Comment 2 Alasdair Kergon 2012-05-01 14:28:06 UTC

Documentation might include: man page, docs team guide, knowledge base.

Internal state might be dumped via signal and/or client commands.

Review & extend/reduce log messages.

Failure modes incl. daemon dying/freezing, uevents getting lost/internal state inconsistent (incl. e.g. a missed 'remove' event)

Comment 3 Petr Rockai 2012-05-20 12:55:52 UTC

I think that this BZ needs to be broken up into actual tasks. Ideas:
- debug and non-debug logging
- on-demand state dump (for lvmdump &c.)
- documentation of failure modes out of our control (udev bugs)
- user level documentation (but I need to know what is actually missing? we
  have example.conf and a manpage, maybe need to update the LVM guide?)

Comment 4 Alasdair Kergon 2012-05-21 00:34:28 UTC

Yes, new bugs for each of those and set them to 'block' this bug.
Then change the Keyword on this bug from 'FutureFeature' to 'Tracking'.  (The new bugs will themselves be 'FutureFeature'.)

Comment 5 Peter Rajnoha 2012-05-22 13:05:21 UTC

Just an instance of the problem related to resilience/robustness: bug #823918.

Comment 8 Petr Rockai 2012-10-12 09:04:40 UTC

the sub-BZs of this have been all POST'd now, what remains to do is documentation. I'll POST this BZ as soon as that's done. I think we are on track to move lvmetad out of tech preview for 6.4, pending QA results...

Comment 9 Petr Rockai 2012-11-19 15:56:39 UTC

Things seem to be going well so far. I have checked in some upstream doc updates. The handbook is in Steve's hands, and I believe he has the info he needs. Therefore, I'm closing this one.