Hello, 

 

I recently had one of my cache drives fail in Unraid. 

I have (had) two 1TB SSDs installed for a cache drive pool and one failed. So far the failed drive won't recognize in unraid or on another PC. 

I have disabled the Docker Service and removed the remaining SSD from the pool. Before I removed it from the pool the SSD stated "Unmountable: Unsupported or no file system"

 

I tired to Mount the SSD using Unassigned Devices but gives me an error "Device '/dev/sdf' failed to mount. Check the syslog for details."

Below is what it generated in the syslog. 

 

I would really like to mount the drive and copy the data over to my array if possible. I also included my diagnostics file.

 

Sep 26 00:11:52 unraid unassigned.devices: Mounting partition 'sdf1' at mountpoint '/mnt/disks/MX_00000000000030532'...
Sep 26 00:11:52 unraid unassigned.devices: Mount cmd: /sbin/mount -t 'btrfs' -o rw,relatime,space_cache=v2,discard '/dev/sdf1' '/mnt/disks/MX_00000000000030532'
Sep 26 00:11:52 unraid kernel: BTRFS info (device sdf1): using crc32c (crc32c-intel) checksum algorithm
Sep 26 00:11:52 unraid kernel: BTRFS info (device sdf1): turning on sync discard
Sep 26 00:11:52 unraid kernel: BTRFS info (device sdf1): using free space tree
Sep 26 00:11:52 unraid kernel: BTRFS error (device sdf1): devid 2 uuid 82b09bec-fe6c-4de2-ad5a-dfe099da7925 is missing
Sep 26 00:11:52 unraid kernel: BTRFS error (device sdf1): failed to read the system array: -2
Sep 26 00:11:52 unraid kernel: BTRFS error (device sdf1): open_ctree failed
Sep 26 00:11:55 unraid unassigned.devices: Mount of 'sdf1' failed: 'mount: /mnt/disks/MX_00000000000030532: wrong fs type, bad option, bad superblock on /dev/sdf1, missing codepage or helper program, or other error.        dmesg(1) may have more information after failed mount system call. '
Sep 26 00:11:55 unraid unassigned.devices: Partition 'MX_00000000000030532' cannot be mounted.

unraid-diagnostics-20230926-0014.zip

Edited September 26, 20232 yr by passive-crutch1376

UD won't mount a degraded pool, assign the device back to a pool and post new diags after array start.

Drive Added Back to Pool and Array Started 

 

unraid-diagnostics-20230926-0803.zip

Sep 26 08:02:18 unraid kernel: BTRFS warning (device sdf1): devid 2 uuid 82b09bec-fe6c-4de2-ad5a-dfe099da7925 is missing
Sep 26 08:02:18 unraid kernel: BTRFS error (device sdf1): failed to read chunk root
Sep 26 08:02:18 unraid kernel: BTRFS error (device sdf1): open_ctree failed

 

This error suggest the pool was not redundant, at least not fully, you can try the recovery options here but most likely they also won't work without the missing device.