Bug 197268 - liblvm2cmd not working properly - causing kill of dmeventd during cmirror fault handling
Summary: liblvm2cmd not working properly - causing kill of dmeventd during cmirror fau...
Alias: None
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: lvm2
Version: 4.0
Hardware: All
OS: Linux
Target Milestone: ---
: ---
Assignee: Jonathan Earl Brassow
QA Contact:
Depends On:
Blocks: 181411
TreeView+ depends on / blocked
Reported: 2006-06-29 18:56 UTC by Jonathan Earl Brassow
Modified: 2007-11-30 22:07 UTC (History)
8 users (show)

Clone Of:
Last Closed: 2006-08-10 21:26:05 UTC

Attachments (Terms of Use)

External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2006:0434 normal SHIPPED_LIVE device-mapper bug fix and enhancement update 2006-08-09 04:00:00 UTC

Description Jonathan Earl Brassow 2006-06-29 18:56:42 UTC
Single machine mirroring is unaffected by this bug.

When a device fails in a mirror, dmeventd is called to handle the event.  This
in turn calls the mirror specific DSO.  The DSO determines that a device has
failed and calls 'vgreduce --removemissing <vg>'.

When that command (run through the liblvm2cmd interface) is called, it loads the
cluster locking library.  Upon the very first call into the locking library, the
program dies.  I haven't determined the cause.  All pointers to functions seem
to be fine, but when _lock_fn is called, dmeventd mysteriously dies.

A _very_ simple workaround is to use 'system()' rather than calling 'lvm2_run'.
 I've tested this, and it works.  I realize that there are memory issues
involved in the forking/etc of this new process, but we have memory issues with
the logging anyway and it's better than having the program die.

Certainly, we will have to fix liblvm2cmd, but I don't understand the problem
there and that could take some time.

Comment 1 Jonathan Earl Brassow 2006-06-29 18:59:12 UTC
This should be considered a blocker.  However, if we get the simple fix in, we
could probably reduce the severity.

Comment 4 Alasdair Kergon 2006-07-04 20:23:59 UTC
We have identified some things that need fixing with the library but have opted
to use the workaround for this release.

Comment 9 Red Hat Bugzilla 2006-08-10 21:26:05 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.


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