Red Hat Bugzilla – Bug 195502
Regression: cluster mirror creation cmd hangs even though mirror gets created
Last modified: 2007-11-30 17:07:25 EST
Description of problem:
With the latest built cmirror rpms an attempt to create a clustered mirror
hangs. There doesn't appear to be any sync issues, or any off by one error, and
the mirror appears to be completely created and in sync from the cluster's point
of view, it's just that the actual cmd to create the mirror never returns.
Version-Release number of selected component (if applicable):
[root@taft-03 ~]# rpm -q cmirror
[root@taft-03 ~]# rpm -q cmirror-kernel
This is the kernel bug that I will be posting a patch for soon.
After the device is created, lvcreate will attempt to zero out the first bunch
of blocks on the device. Doing this will cause writes to colide with resync'ing
regions. This causes a hang in the 2.6.9-39.EL kernel.
To test and see that this is the bug I think it is, you can do 'lvcreate
--nosync ...' and you should not see the hang on lvcreate. This is because
--nosync says that it will not initially re-sync the mirror - meaning there can
be no colision.
This hang does not happen when using the --nosync on creation.
please retest with kernel > 39.EL
committed in stream U4 build 39.2. A test kernel with this patch is available
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.