I recently created a a share and transferred data to it but got a message from Unraid 6.83 stating the cache drive was almost out of space. I turned off the cache on the share volume. Stopped the array and shutdown the server and then rebooted the server and data is now missing. I then shutdown the server for a few days and booted up today now all the shared folders are missing. But oddly the main screen it shows the array is online with the exception of the cache disk. It also shows the total size of the array and how much space is used and what is available.  Please see attached photos. If anyone can point me on how to recover the data it would be appreciated.

Please post the diagnostics: Tools -> Diagnostics

See attached diagnostic file

unraid-genesis-diagnostics-20210407-1313.zip

Cache filesystem is corrupt, see here for some recovery options.

 

Shares are not working because shfs segfaulted, rebooting should fix it.

Okay, rebooted and the shares returned, thank you. But I am still missing data and the docker for unifi controller has not returned.

20 minutes ago, Drakker said:

But I am still missing data and the docker for unifi controller has not returned.

 

48 minutes ago, JorgeB said:

Cache filesystem is corrupt, see here for some recovery options.

 

Okay, will try later this evening.  Thank you replying so quickly and providing guidance to a newbie. I will post and let you know the status.

Hi,

 

I looked at the provided instructions and I'm lost I know that i need to get SSH to the Unraid server and I've figured out which drive is the cache drive but need to know what to do next. Please see below for the drives I have listed.

 

SCSI Devices

[0:0:0:0]    disk    Lexar    USB Flash Drive  1100  /dev/sda   8.01GB (Unraid)
[1:0:1:0]    cd/dvd  MATSHITA DVD-ROM UJDA780  1.50  /dev/sr0        -
[3:0:0:0]    disk    ATA      WDC WD20EZRZ-00Z 0A80  /dev/sdc   2.00TB (Part of Array)
[4:0:0:0]    disk    ATA      WDC WD20EZRZ-00Z 0A80  /dev/sdd   2.00TB (Part of Array)
[5:0:0:0]    disk    ATA      WDC WD20EZRX-00D 0A80  /dev/sde   2.00TB (Part of Array)
[6:0:0:0]    disk    ATA      WDC WD20EZRZ-00Z 0A80  /dev/sdf   2.00TB (Part of Array)
[7:0:0:0]    disk    ATA      WDC WD30EZRX-00S 0A80  /dev/sdg   3.00TB (Parity Drive)
[9:0:0:0]    disk    Adaptec  5405Z Volume     V1.0  /dev/sdb    999GB (Cache Drive) - (Cache Drive Unmountable: no file system)

12 hours ago, Drakker said:

I know that i need to get SSH to the Unraid server

You can also use the terminal built-in the WebGUI.

 

12 hours ago, Drakker said:

/dev/sdb    999GB (Cache Drive)

Use /dev/sdb1, also note that using a raid volume for cache is a very bad idea, btrfs should have direct access to the actual devices.

WARNING:

    Do not use --repair unless you are advised to do so by a developer
    or an experienced user, and then only after having accepted that no
    fsck can successfully repair all types of filesystem corruption. Eg.
    some software or hardware bugs can fatally damage a volume.
    The operation will start in 10 seconds.
    Use Ctrl-C to stop it.
10 9 8 7 6 5 4 3 2 1parent transid verify failed on 483222519808 wanted 3293310 found 3289355
parent transid verify failed on 483222568960 wanted 3293310 found 3289355
parent transid verify failed on 483222601728 wanted 3293310 found 3289353
parent transid verify failed on 483222601728 wanted 3293310 found 3289353
parent transid verify failed on 483222601728 wanted 3293310 found 3289353
Ignoring transid failure
leaf parent key incorrect 483222601728
ERROR: failed to read block groups: Operation not permitted
ERROR: cannot open file system

Starting repair.
Opening filesystem to check...

Connection established.
To escape to local shell, press 'Ctrl+Alt+]'.

WARNING! The remote SSH server rejected X11 forwarding request.
Linux 4.19.107-Unraid.
root@UNRAID-GENESIS:~# mkdir /x
root@UNRAID-GENESIS:~# mount -o usebackuproot,ro /dev/sdb1 /x
mount: /x: wrong fs type, bad option, bad superblock on /dev/sdb1, missing codepage or helper program, or other error.

root@UNRAID-GENESIS:~# mount -o degraded,usebackuproot,ro /dev/sdb1 /x
mount: /x: wrong fs type, bad option, bad superblock on /dev/sdb1, missing codepage or helper program, or other error.

root@UNRAID-GENESIS:~# mount -o ro,notreelog,nologreplay /dev/sdb1 /x
mount: /x: wrong fs type, bad option, bad superblock on /dev/sdb1, missing codepage or helper program, or other error.

root@UNRAID-GENESIS:~# btrfs check --repair /dev/sdb1
enabling repair mode
WARNING:

    Do not use --repair unless you are advised to do so by a developer
    or an experienced user, and then only after having accepted that no
    fsck can successfully repair all types of filesystem corruption. Eg.
    some software or hardware bugs can fatally damage a volume.
    The operation will start in 10 seconds.
    Use Ctrl-C to stop it.
10 9 8 7 6 5 4 3 2 1
Starting repair.
Opening filesystem to check...
parent transid verify failed on 483222519808 wanted 3293310 found 3289355
parent transid verify failed on 483222568960 wanted 3293310 found 3289355
parent transid verify failed on 483222601728 wanted 3293310 found 3289353
parent transid verify failed on 483222601728 wanted 3293310 found 3289353
parent transid verify failed on 483222601728 wanted 3293310 found 3289353
Ignoring transid failure
leaf parent key incorrect 483222601728
ERROR: failed to read block groups: Operation not permitted
ERROR: cannot open file system
root@UNRAID-GENESIS:~#

Best chance of recovery for that issue is btrfs restore, looks like you tried everything except that, including check --repair which should only be done as a last resort.

Okay, so how would I type the btrfs restore command for the cache drive, i've look at various threads and its confusing

It's also in the linked FAQ entry, option #2.

 

 

So I tried this:

 

btrfs rescue chunk-recover -v /dev/sdb1

 

Unrecoverable Chunks:

Total Chunks:        931
  Recoverable:        931
  Unrecoverable:    0

Orphan Block Groups:

Orphan Device Extents:

Check chunks successfully with no orphans
Chunk tree recovered successfully
root@UNRAID-GENESIS:~#

So I tried this:

 

btrfs restore -v /dev/sdb1 /media/cache

 

parent transid verify failed on 483223683072 wanted 3293310 found 3289357
parent transid verify failed on 483223683072 wanted 3293310 found 3289357
parent transid verify failed on 483223683072 wanted 3293310 found 3289357
Ignoring transid failure
ERROR: child eb corrupted: parent bytenr=483222257664 item=0 parent level=2 child level=2
Error searching -5
root@UNRAID-GENESIS:~#

Like mentioned there you can try -vi to ignore the errors.