Occassional problems with unfreeze

[Hrishikesh Barua <talonx@xxxxxxxxx>]

We use XFS on Amazon EBS on Ubuntu 12.04.3, kernel "3.2.0-54-virtual".

Our backup scripts invoke "xfs_freeze -f" before taking a snapshot to ensure filesystem consistency. After the snapshot is taken, we invoke "xfs_freeze -u".

Recently, we have observed that some of these unfreeze calls exit with code 255. This results in a frozen filesystem, processes queuing up and us having to reboot the EC2 instance. Invoking freeze -u manually results in multiple processes like this -

ÂÂÂÂ 17628 ?ÂÂÂÂÂÂÂ DÂÂÂÂÂ 0:00 /usr/sbin/xfs_io -F -r -p xfs_freeze -x -c thaw /mysql-vol-a
ÂÂÂÂ 17694 ?ÂÂÂÂÂÂÂ DÂÂÂÂÂ 0:00 /usr/sbin/xfs_io -F -r -p xfs_freeze -x -c thaw /mysql-vol-a

A search on this list reveals at least one other instance of this problem - http://oss.sgi.com/archives/xfs/2013-01/msg00437.html

No resolution seems to have happened there. Is this a known bug, or has it been fixed since (I'm running xfsprogs 3.1.7) ?

Regards

Hrish