Bug 817776

Summary: Improve resilience & robustness of lvmetad
Product: Red Hat Enterprise Linux 6 Reporter: Alasdair Kergon <agk>
Component: lvm2Assignee: Petr Rockai <prockai>
Status: CLOSED NEXTRELEASE QA Contact: Cluster QE <mspqa-list>
Severity: medium Docs Contact:
Priority: high    
Version: 6.4CC: agk, cmarthal, dwysocha, heinzm, jbrassow, msnitzer, prajnoha, prockai, syeghiay, thornber, zkabelac
Target Milestone: pre-dev-freezeKeywords: Tracking
Target Release: 6.4   
Hardware: All   
OS: Linux   
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:
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.