Cache pool unmountable

[devin.buell]

I made a mistake thinking I could reduce my cache pool size and removed two drives and then restarted the array. This resulted in a now obvious messaging saying two many disks missing and that the pool was unmountable. I added the drives back in the same order and restarted the array but have the same error message. 

 

Is it possible to restore my pool or do I need to manually pull of the files from one of the drives and then rebuilt the pool? 

 

Diagnostic files attached. 

buellvault-diagnostics-20230320-2130.zip

[JorgeB]

Post the output of:

btrfs fi show

 

[devin.buell]

Sorry for the delay - was traveling. Output is below 

 

bad tree block 2386712559616, bytenr mismatch, want=2386712559616, have=0
Couldn't read tree root
Label: none  uuid: b242ecb7-0712-4962-8ae2-ac3d49ad64fd
        Total devices 4 FS bytes used 142.30GiB
        devid    3 size 465.76GiB used 82.03GiB path /dev/sdb1
        devid    4 size 465.76GiB used 82.03GiB path /dev/sde1
        *** Some devices missing

[devin.buell]

THis is the output after I start the array: 

 

root@BuellVault:~# btrfs fi show
Label: none  uuid: 19173620-859f-437e-b39c-fbe64123cf0a
        Total devices 1 FS bytes used 348.00KiB
        devid    1 size 1.00GiB used 126.38MiB path /dev/loop2

bad tree block 2386712559616, bytenr mismatch, want=2386712559616, have=0
Couldn't read tree root
Label: none  uuid: b242ecb7-0712-4962-8ae2-ac3d49ad64fd
        Total devices 4 FS bytes used 142.30GiB
        devid    3 size 465.76GiB used 82.03GiB path /dev/sdb1
        devid    4 size 465.76GiB used 82.03GiB path /dev/sde1
        *** Some devices missing
 

[JorgeB]

Stop the array and post output of:

btrfs-select-super -s 1 /dev/sdc1

and

btrfs-select-super -s 1 /dev/sdd1

 

[devin.buell]

Output below: 

 

root@BuellVault:~# btrfs-select-super -s 1 /dev/sdc1
using SB copy 1, bytenr 67108864
root@BuellVault:~# btrfs-select-super -s 1 /dev/sdd1
using SB copy 1, bytenr 67108864
root@BuellVault:~# 
 

[JorgeB]

On 3/21/2023 at 9:13 AM, JorgeB said:

Post the output of:

btrfs fi show

again please

[devin.buell]

root@BuellVault:~# btrfs fi show
Label: none  uuid: b242ecb7-0712-4962-8ae2-ac3d49ad64fd
        Total devices 4 FS bytes used 142.30GiB
        devid    1 size 447.13GiB used 63.00GiB path /dev/sdc1
        devid    2 size 447.13GiB used 63.00GiB path /dev/sdd1
        devid    3 size 465.76GiB used 82.03GiB path /dev/sdb1
        devid    4 size 465.76GiB used 82.03GiB path /dev/sde1

root@BuellVault:~# 

[JorgeB]

OK, now with array stopped, unassign all devices from that pool, start array, stop array, re-assign all 4 pool devices, start array, post new diags if it doesn't mount.

[devin.buell]

You are amazing! The pool has been restored. Going to make a fresh backup of everything now!