I have 2 caches (1 120GB OCZ SSD and 1 480GB PNY SSD). I think the PNY started having issues a few weeks back (sorry cant remember which one). Now I am getting the 2 errors below on my drives. My appdata is cache only (which I read to be best practice on these forums I believe) so I need to try to get the data back if possible. There isnt anything critical on there but I would prefer not to have to redo all of my dockers.

 

Diagnostics attached.

 

 

Unmountable: No file system (no btrfs devices)

Device is part of cache pool

 

 

jordan-diagnostics-20201206-2001.zip

Constant errors on one of the cache devices:

Dec  6 18:57:07 Jordan kernel: sd 1:0:0:0: [sdb] tag#12 UNKNOWN(0x2003) Result: hostbyte=0x04 driverbyte=0x00
Dec  6 18:57:07 Jordan kernel: sd 1:0:0:0: [sdb] tag#12 CDB: opcode=0x28 28 00 00 00 00 40 00 00 01 00
Dec  6 18:57:07 Jordan kernel: print_req_error: I/O error, dev sdb, sector 64
Dec  6 18:57:07 Jordan kernel: sd 1:0:0:0: [sdb] tag#27 UNKNOWN(0x2003) Result: hostbyte=0x04 driverbyte=0x00
Dec  6 18:57:07 Jordan kernel: sd 1:0:0:0: [sdb] tag#27 CDB: opcode=0x28 28 00 00 00 00 40 00 00 20 00
Dec  6 18:57:07 Jordan kernel: print_req_error: I/O error, dev sdb, sector 64
Dec  6 18:57:07 Jordan kernel: sd 1:0:0:0: [sdb] tag#28 UNKNOWN(0x2003) Result: hostbyte=0x04 driverbyte=0x00
Dec  6 18:57:07 Jordan kernel: sd 1:0:0:0: [sdb] tag#28 CDB: opcode=0x28 28 00 00 00 00 40 00 00 08 00
Dec  6 18:57:07 Jordan kernel: print_req_error: I/O error, dev sdb, sector 64

 

You can try these options to recover the data, then also see here for better pool monitoring.

So i tried that and got the message below. fdisk -l doesnt show sdb. Restore also didnt work. Per your instructions I also tried sdc1 as well since my cache is a pool. I was able to restore some data from sdc using btrfs restore

 

Thanks,

 

root@Jordan:~# mount -o usebackuproot,ro /dev/sdb1 /x
mount: /x: can't read superblock on /dev/sdb1.

 

 

btrfs restore -v /dev/sdb1 /mnt/disk2/restore
No valid Btrfs found on /dev/sdb1
Could not open root, trying backup super
No valid Btrfs found on /dev/sdb1
Could not open root, trying backup super
No valid Btrfs found on /dev/sdb1
Could not open root, trying backup super

 

root@Jordan:~# mount -o usebackuproot,ro /dev/sdc1 /x
mount: /x: wrong fs type, bad option, bad superblock on /dev/sdc1, missing codepage or helper program, or other error.

 

root@Jordan:~# mount -o degraded,usebackuproot,ro /dev/sdb1 /x
mount: /x: can't read superblock on /dev/sdb1.
root@Jordan:~# mount -o degraded,usebackuproot,ro /dev/sdc1 /x
mount: /x: wrong fs type, bad option, bad superblock on /dev/sdc1, missing codepage or helper program, or other error.

 

 

 

 

 

Anybody?

Like mentioned in the FAQ if the options there don't work best bet is to use the btrfs mailing list and/or their IRC channel for help.