My array says one of my drives is unmountable, though the SMART report is fine. What should I do? Re-Format? Can I then rebuild from Parity? Replace the drive to be safe?

Thanks

-B

DO NOT FORMAT THE DRIVE!!!!

 

 

Wait until you get more expert advice.

 

Let me repeat: DO NOT FORMAT THE DRIVE!!!

Post your diagnostics, Tools -> Diagnostics

Just to further stress what's already been said. DO NOT FORMAT. If you format the only thing you will be able to rebuild is a formatted drive. A freshly formatted drive is an empty filesystem. Surely you don't want that.

 

So many people don't seem to know what formatting actually is/does. Format means "write an empty filesystem to this disk". That is what it has always meant in every operating system you have ever used. unRAID treats this write exactly like it does any other write, by updating parity. So after the format parity will agree you have an empty filesystem and that is what you would get if you rebuild after a format.

Attached are the diagnostics...got it don't format... what should i do?

clarach-diagnostics-20161027-2205.zip

You need to check filesystem on disk7 (md7), I'd do it before rebuilding:

 

https://lime-technology.com/wiki/index.php/Check_Disk_Filesystems#Drives_formatted_with_XFS

 

Then, and since SMART looks good, try rebuilding to same disk.

Got this Error:

 

 

Phase 1 - find and verify superblock...

Phase 2 - using internal log

        - zero log...

ERROR: The filesystem has valuable metadata changes in a log which needs to

be replayed.  Mount the filesystem to replay the log, and unmount it before

re-running xfs_repair.  If you are unable to mount the filesystem, then use

the -L option to destroy the log and attempt a repair.

Note that destroying the log may cause corruption -- please attempt a mount

of the filesystem before doing this.

 

 

what should I do next?

Use the -L option.

The filesystem mounts fine if it's mounted separate from the array....should I still destroy the log?

The filesystem mounts fine if it's mounted separate from the array....should I still destroy the log?

Since the disk is disabled, the array drive is actually the emulated drive. Mounting the physical drive out of the array is not the same, and the physical drive is technically out-of-sync with parity.

 

The question is whether it would be better to fix the emulated drive and then rebuild, or set a new config with the physical drive and rebuild parity instead.

 

Do you have another disk you can rebuild to? That would allow you to try it both ways.

 

You can use -L on the emulated disk, usually there's no data loss, you can then check if all looks fine before rebuilding (you can also compare the contents with the actual disk), but like trurl suggested rebuilding to a spare with leave you with more options.

I've got a spare drive that's identical.

I should add that to the array and then rebuild from parity? then if anything's missing I can just transfer from the old drive??

Yes, you can do that, but first run xfs_repair -L on the emulated disk to see what you're going to be rebuilding.

the emulated disk is /dev/md[#] right? Or should I run it right from the gui? or command line?

You can use either, it's /dev/md7