I just did a BIOS update to my server and after the reboot my cache drive says "Unmountable: No File System"  The filesystem is formatted as btrfs and it's a single drive cache. If I start the array in maintenance mode and run a "check" on the drive I get the output below. Is there anything I can do to get this drive back? Since it holds all of my appdata It would be really beneficial if I could get it back without having to completely rebuild all of my docker containers.

 

 

checking extents corrupt extent record: key 77388988416 168 12288 Data backref 77388988416 root 5 owner 29116341 offset 0 num_refs 0 not found in extent tree Incorrect local backref count on 77388988416 root 5 owner 29116341 offset 0 found 1 wanted 0 back 0x5123090 backpointer mismatch on [77388988416 12288] checking free space cache checking fs roots checking csums checking root refs Checking filesystem on /dev/sde1 UUID: 42b3df23-f523-424c-a590-2278dd1d8e46 found 725679960064 bytes used, no error found total csum bytes: 706884908 total tree bytes: 1579859968 total fs tree bytes: 478265344 total extent tree bytes: 63406080 btree space waste bytes: 461863403 file data blocks allocated: 774895443968 referenced 723464388608

Edited January 12, 20188 yr by IndianaJoe1216

Please post your diagnostics: Tools -> Diagnostics

 

 

Attached. Thanks.

glados-diagnostics-20180112-0811.zip

Filesystem is corrupt, with btrfs it's best to format and start over than repairing, you can use this to try and recover any important data:

 

https://lime-technology.com/forums/topic/46802-faq-for-unraid-v6/?do=findComment&comment=543490

 

Thanks Johnnie, Whether or not I can recover, should I change the file system to xfs or something other than btrfs?

It depends on what you value, if you don't plan on creating a pool later and don't care for snapshots and/or checksums probably best to use xfs.

I originally had it in a pool, but the 2nd drive was an sshd that was failing so I removed it and went to a single drive. I would like to get another 1TB SSD and turn it into a pool again. I wasn't aware that snapshots were an option though so it sounds like I want to go back to btrfs.

btrfs especially in a single device mode, is currently pretty stable, if this was not an isolated incident it most likely indicates a problem somewhere, like a bad cable/connection, bad RAM, etc.

Yeah this was the only time I have had an issue. I did the restore this morning and backed up as much as possible onto the array and then reformatted the drive into btrfs and am currently moving the files back off of the array to the newly formatted cache. Thanks for the help!