PerryS

That is supper bizarre as it has always been set up as a redundant pool with 2 drives. Any idea what might have caused this to happen? I'm assuming whatever happened happened during the process of tying to replace one of the cache drives. But I followed the portion of the Official Unraid Manual to the letter when I did. Is there any chance of recovering the data off of that drive at this point or am I just completely out of luck? Also thank you so much for your time @JorgeB. I really appreciate all of the advice.

Adding the one device (sdk) to the cache pool and starting the array yields this: I am attaching the diagnostics export below. vader-1-diagnostics-20240401-1703.zip

It makes sense to me that I wouldn’t be able to restore the data on sdl but is there not a way to just get sdk to mount? As I understand it being that it was a two device pool wouldn’t that mean the entirety of the data was stored on both disks? So if there is a way to mount sdk then I could backup the contents and the rebuild the pool all together.

Sdl was the second pool device. It mounts fine but contains no data.

Hello, I'm in a very similar situation as Adrian here where after trying to replace a cache drive one of the 2 drives in the pool seams to have been wiped completely and the other is unmountable with the following being generated in the log: Mar 30 23:10:09 Vader-1 unassigned.devices: Mounting partition 'sdk1' at mountpoint '/mnt/disks/TPBF2209290060500231'... Mar 30 23:10:09 Vader-1 unassigned.devices: Mount cmd: /sbin/mount -t 'btrfs' -o ro,relatime,space_cache=v2,discard '/dev/sdk1' '/mnt/disks/TPBF2209290060500231' Mar 30 23:10:10 Vader-1 unassigned.devices: Mount of 'sdk1' failed: 'mount: /mnt/disks/TPBF2209290060500231: wrong fs type, bad option, bad superblock on /dev/sdk1, missing codepage or helper program, or other error. dmesg(1) may have more information after failed mount system call. ' Mar 30 23:10:10 Vader-1 unassigned.devices: Partition 'TPBF2209290060500231' cannot be mounted. sdk and sdl were the original pool members. "btrfs fi show" returns: warning, device 2 is missing warning, device 2 is missing ERROR: cannot read chunk root Label: none uuid: 488a4ce6-34fe-420f-a8ef-9e5862e79a28 Total devices 2 FS bytes used 45.95GiB devid 1 size 953.87GiB used 45.00GiB path /dev/sdk1 *** Some devices missing Label: none uuid: 7f4fbf85-9803-4a4f-a951-3a6b45414213 Total devices 1 FS bytes used 144.00KiB devid 1 size 953.87GiB used 2.02GiB path /dev/sdl1 "sfdisk /dev/sdk" returns: Welcome to sfdisk (util-linux 2.38.1). Changes will remain in memory only, until you decide to write them. Be careful before using the write command. Checking that no-one is using this disk right now ... OK Disk /dev/sdk: 953.87 GiB, 1024209543168 bytes, 2000409264 sectors Disk model: TEAM T2531TB Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0xb78f201f Old situation: Device Boot Start End Sectors Size Id Type /dev/sdk1 2048 2000409263 2000407216 953.9G 83 Linux Type 'help' to get more information. >>> Thank you in advance and any help at all would be greatly appreciated.