Unmountable: No file system

[SkippyAlpha]

This is my first time posting here so please let me know if I've posted correctly!

 

On Saturday 10/20 I was informed by a friend that he was unable to access my Plex server. I went to check it out and realized that the server seemed locked up, couldn't access webui nor any of the dockers running on it (plex, radarr, sonarr, ombi etc.) So I (dumbly) did an unclean shutdown of the server. After it restarted everything came back up as normal and everything was working with the exception of disk 7 in my array... which said it was "Unmountable: No file system" I tried rebooting the server again but it was still like this. The array drives are all formatted as btrfs (will probably be switching them to xfs after this). I stopped the array, removed disk 7, and restarted the array, however it still says the same message even with no device in that slot. Also I cannot mount the disk in UD. I've tried all of the recovery options found in the post I linked below by johnnie.black, with the exception of the very last option (destructive recovery). I wanted to wait until I posted here before I tried that option. Also I found this on an arch linux forum https://bbs.archlinux.org/viewtopic.php?id=233724 and was wondering if this might be able to help me, also haven't tried this yet. I'm at work right now but once I can get home I can try to provide any necessary logs. I've also attached a screenshot of my array. Thanks!

 

[SkippyAlpha]

Here is this syslog. Also another question, why am I unable to rebuild the disk from parity? Is it because this is already the state that the parity remembers everything in? That would make sense as to why it still shows the error even when the disk is emulated I suppose

elmserver-syslog-20181022-1544.zip

[itimpi]

32 minutes ago, Sven88 said:

Here is this syslog. Also another question, why am I unable to rebuild the disk from parity? Is it because this is already the state that the parity remembers everything in? That would make sense as to why it still shows the error even when the disk is emulated I suppose

elmserver-syslog-20181022-1544.zip

Parity remembers the ‘physical’ contents of the drive - not the logical contents.    As such it is unaware of file systems or individual files.    File system corruption is therefore not recoverable using parity - it can only be recovered using file system repair tools.

[SkippyAlpha]

@itimpi Gotcha, do you think I should go ahead with trying "btrfs check --repair /dev/sdX1" on the disk? I still have it out of the array. Or is there anything else I should try first?

[JorgeB]

Basically btrfs check --repair should only be run if a btrfs maintainer told you to do it, since it can make things even worse, so if the other non destructive recovery options didn't work and you want the best chance of recovering your data ask for help on the btrfs mailing list, if the data it's not that important or you're not whiling to use the mailing list try check --repair as a last resort.

[JorgeB]

P.S. if you want to keep using btrfs convert the metadata to dup (duplicate) in all disks, like so:

 

btrfs balance start -mconvert=dup /mnt/diskX

This should be the default and I already asked LT to change it more than once, unfortunately it wasn't done yet, can't say for sure that would help in this case, but it's very likely it would since you have metadata corruption, and that can cause the loss of the entire filesystem.

 

 

[SkippyAlpha]

Hmm alright I may try changing the metadata to dup. I really only used btrfs because it seemed like the modern thing to use, but it just seems too fragile and finicky. Do you know if there is an easy way in unraid to make a copy of the disk so that I can continue trying things on the disk without worry? Like a copy of the disk at the bit level?

[SkippyAlpha]

Also through googling I'm seeing mentions of a couple commands "init-csum-tree" and "init-extent-tree" they are talked about like they're really dangerous. Any experience with these?

[SkippyAlpha]

Aha! Pretty sure I've lost it all lol. I guess thats one of the beauties of Unraid, I ONLY lost one disks worth of media, and not all of it, movies and tv shows that I can get back. Oh well, live and learn I suppose.

 

EDIT: Plus Plex has a trashcan icon over all of the media that it cant find, so I know what I lost. Not the end of the world

Edited October 22, 2018 by Sven88

[JorgeB]

8 hours ago, Sven88 said:

Do you know if there is an easy way in unraid to make a copy of the disk so that I can continue trying things on the disk without worry? Like a copy of the disk at the bit level?

You can rebuild to a different disk.

 

8 hours ago, Sven88 said:

Also through googling I'm seeing mentions of a couple commands "init-csum-tree" and "init-extent-tree" they are talked about like they're really dangerous. Any experience with these?

Not really, and like check --repair it can make things worse if the wrong option is used.

 

 

[SkippyAlpha]

4 hours ago, johnnie.black said:

You can rebuild to a different disk.

Doh! I didn't even think of that! Oh well, I'll remember it for the future. I guess this post can be closed now