We had three HDD failures back-to-back-to-back on a RAID-5 setup. Each of these disks has 2 partitions called 04 and 05. Only HDDs that contained 04 failed. 04 is xfs while the other partition (05) is reiserfs and is fine. For 04, the directories under 04 are accessible but they contain no data. I find it suspicious that 04 is on all the failed HDDs and not accessible but 05 is fine. I also think 3 HDDs failures in a row seems extremely unlikely but not impossible.

What is the recovery procedure for restoring xfs file systems? I have not tried anything yet but I believe the HDDs are fine and that they just can't see the data at the moment.

Usually I do the following:

1. First off mount the partition, this will restore (if possible) the internal log.
2. Then umount it and run "xfs_check /dev/device"
3. Then "xfs_repair /dev/device"

If this doesn't work then you may have a problem. Hope it works...

The risk of losing data from an xfs partition is far greater than that for any other type of filesystem. Files on are open during a power or other failure are filled with zeros by xfs so they may be damaged beyond repair; other filesystems are slower but tend to do better at recovering after a failure.