The system froze sometime in the middle of the night, and oddly... the --backup-file I specified last night is missing. Is there any reason that mdadm would unlink it for a short span of time during the reshape? The raid5 array was 4x500GB drives, I was reshaping to raid6 by adding another 500gb drive. $ sudo mdadm --assemble /dev/md1 mdadm: Failed to restore critical section for reshape, sorry. Possibly you needed to specify the --backup-file FC12, using $ mdadm --version mdadm - v3.1.1 - 19th November 2009 sudo mdadm --assemble /dev/md1 --backup-file=/.MEDIA/tmp/mdadm.backup mdadm: backup file /.MEDIA/tmp/mdadm.backup inaccessible: No such file or directory mdadm: Failed to restore critical section for reshape, sorry. [rrauenza@tendo ~]$ Hmmm... I wonder if I hit this - as I might have had a drive failure based on some extra noise at bootup: 3/ There is another bug where by if one of the devices in the array dies during the reshape, the backup process stops working correctly with the result that the reshape goes much faster but the backup is completely useless. If you crash during the reshape after a failed device, you will probably lose data. If you try to stop and restart the array after one device has failed, the restart will fail. However this is still the safest thing to do. I will try to put out some updates to mdadm so that you can reassemble the array safely in this case (and of course, fix the problem so that the backup is maintained throughout the entire run). I'm currently running a smartctl -t long against all of the drives... Any other ideas in the meantime? I suspect I've lost my 1.5 TB array :( Rich -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html