Cache Drive - Power Outage/Surge

[lance-tek]

A week or so ago, we lost power.  I'm not sure of the details as I have not been home.

Anyway, I'm getting an error for the [btrfs] cache drive... "Unmountable: Wrong or no file system"

 

I started the array in diagnostic mode and ran the check on the cache drive.  I haven't changed anything or tried to do anything since I am pretty much a novice and hope to keep the data that might be recoverable...

 

[1/7] checking root items
[2/7] checking extents
incorrect local backref count on 198720106496 root 5 owner 9032415 offset 0 found 1 wanted 0 back 0x306e28b0
backpointer mismatch on [198720106496 16384]
incorrect local backref count on 199878418432 root 5 owner 54485 offset 2778279936 found 1 wanted 0 back 0x5285f6e0
backpointer mismatch on [199878418432 4096]
incorrect local backref count on 320401063936 root 5 owner 54485 offset 53953183744 found 1 wanted 0 back 0x5a4a91e0
backpointer mismatch on [320401063936 16384]
ERROR: errors found in extent allocation tree or chunk allocation
[3/7] checking free space tree
[4/7] checking fs roots
[5/7] checking only csums items (without verifying data)
[6/7] checking root refs
[7/7] checking quota groups skipped (not enabled on this FS)
Opening filesystem to check...
Checking filesystem on /dev/sde1
UUID: 1e82dabf-077d-499b-912c-1a97811288ba
found 165126217728 bytes used, error(s) found
total csum bytes: 157326020
total tree bytes: 1525940224
total fs tree bytes: 677117952
total extent tree bytes: 557547520
btree space waste bytes: 356864765
file data blocks allocated: 1970767323136
 referenced 143412604928

 

 

At this point what should I do next?

[JorgeB]

Please post the diagnostics after array start.

[lance-tek]

tower-diagnostics-20230410-1424.zip

OK, that is attached as is the SMART report 🙂 

tower-smart-20230410-1425.zip

[lance-tek]

I did have some data stored as "cache drive only" so I'm guessing that data would be lost if I just formatted the drive, right?

[JorgeB]

If the log is the only problem this might help:

btrfs rescue zero-log /dev/sde1

 

[lance-tek]

7 hours ago, JorgeB said:

If the log is the only problem this might help:

btrfs rescue zero-log /dev/sde1

 

That's all it took!  I ran that command and then restarted my unraid tower and all is working again 🙂 

Thanks!!!!

 

[JorgeB]

Good, this issue has been know to reoccur, so make sure backups are up to date and if it does happen again recommend reformatting the pool, though the same command should fix it again.