[Solved] Unmountable disk that will mount fine manually

[bubbaQ]

I was replacing a couple of old disks with new ones.  I precleared and added the new ones to the array, started the array, formatted the new drives (XFS)  then copied the files from the old disks to the new ones via the disk shares.  Then I stopped the array to unassigned the old disks and changed the disk assignments for the new ones.

 

When I started the array, one of the new disks shows as unmountable.  So I stopped the array, and mounted it by hand and it mounts fine and all the data is accessible.

 

Tried again to restart the array and unRAID complains it is unmountable.  xfs_repair -n shows no problems and the syslog shows nothing unusual.

 

Suggestions?

[bubbaQ]

Solved... but weird. 

 

If I changed the unmountable drive from disk4 to disk14, left disk4 unassigned, the array mounts with no problems.  Change it back to disk4, and the disk was unmountable to unRAID but mounted fine manually.

 

So I wiped out the disk config and reassigned all the drives from scratch, and it is all working now. 

[JonathanM]

Sounds like you may have run into the format auto detection "bug". If a particular disk slot format option is set to auto, it may or may not correctly detect the pre-existing format, but if you specify the known correct format type for that drive, it will mount just fine.