thebluespirit

I was finally able to get the new ZFS pool to start properly. There was a file that existed in /mnt/cache which was preventing the directory from being removed which was interrupting the formatting process. After removing the file I formatted the cache pool drives again and they were able to be mounted. I still don't know what happened to the original pool, but as I mentioned half of it was very old and half was very recently added. Not sure why the new drive wasn't partitioned by UnRAID, but that was a hint that something wasn't quite right. Thanks for your help @JorgeB

Thanks Jorge, since I was able to mount it RO, I copied all the data off the cache drives and onto the array. I've had this cache pool for many years and through many UnRAID versions prior to adding the new disk, so I'm thinking it might be the best use of time to just start fresh with a new cache pool, then copy the data back. What I've done is: stop the array and erase the current cache pool, then removed it. I then added a new cache pool with 2 slots. I clicked on the first cache drive which in this case I will make the WD (sdf) and changed the file system to zfs striped (Which I believe should accomplish the same as btrfs single mode in the case of using all data on both drives) Changed the file system from auto to zfs Changed the allocation type to striped (2 devices) Started the array Formatted the unmountable cache disks using the format button at the button with the other array controls Once they finish formatting, in the GUI I am getting the same unmountable: wrong or no filesystem error. diagnostics-20250625-1041.zip

Later today I will reboot and post new diagnostics. Though, the ones I sent were gathered after a reboot. Not really. The way it went down was I had the 250GB cache drive for years in a single drive pool, that's the Samsung (sdc1). Several weeks ago I got the 1TB WD drive (sdf). I expanded the pool slots to 2, added the new drive, and converted the pool to single mode so I could utilize all the space from both drives. The only thing I remember doing that deviated from default behavior was changing the pool from raid1 to single mode.

I recently stopped and started my array to made a change to an SMB setting and when the array came back up, my two-drive single mode cache pool won't mount. In the GUI the error shown is: "Unmountable: wrong or no filesystem". The unraid log shows: Jun 24 15:50:06 emhttpd: cache: btrfs verify devices Jun 24 15:50:06 emhttpd: /sbin/btrfs filesystem show af326f9e-a439-4fd0-b2ef-57c6d8da236c 2>&1 Jun 24 15:50:06 emhttpd: Label: none uuid: af326f9e-a439-4fd0-b2ef-57c6d8da236c Jun 24 15:50:06 emhttpd: #011Total devices 2 FS bytes used 502.52GiB Jun 24 15:50:06 emhttpd: #011devid 1 size 232.88GiB used 232.88GiB path /dev/sdc1 Jun 24 15:50:06 emhttpd: #011devid 2 size 931.51GiB used 335.00GiB path /dev/sdf Jun 24 15:50:06 emhttpd: cache: cannot import with misplaced devices Jun 24 15:50:06 emhttpd: shcmd (4542): rmdir /mnt/cache Jun 24 15:50:06 root: rmdir: failed to remove '/mnt/cache': Directory not empty Jun 24 15:50:06 emhttpd: shcmd (4542): exit status: 1 Jun 24 15:50:06 emhttpd: cache: mount error: wrong or no file systemYet the file system seems to be intact on both drives, and both are present. I can even mount the pool read only using mount -o rescue=all,ro /dev/sdc1 /temp Output of btrfs fi show : Label: none uuid: af326f9e-a439-4fd0-b2ef-57c6d8da236c Total devices 2 FS bytes used 502.52GiB devid 1 size 232.88GiB used 232.88GiB path /dev/sdc1 devid 2 size 931.51GiB used 335.00GiB path /dev/sdf btrfs check output for each drive with no errors: Checking filesystem on /dev/sdc1 UUID: af326f9e-a439-4fd0-b2ef-57c6d8da236c [1/8] checking log skipped (none written) [2/8] checking root items [3/8] checking extents [4/8] checking free space tree [5/8] checking fs roots [6/8] checking only csums items (without verifying data) [7/8] checking root refs [8/8] checking quota groups skipped (not enabled on this FS) found 539572510720 bytes used, no error found total csum bytes: 391171280 total tree bytes: 1112637440 total fs tree bytes: 493502464 total extent tree bytes: 156663808 btree space waste bytes: 189219902 file data blocks allocated: 16886634491904 referenced 482911248384Checking filesystem on /dev/sdf UUID: af326f9e-a439-4fd0-b2ef-57c6d8da236c [1/8] checking log skipped (none written) [2/8] checking root items [3/8] checking extents [4/8] checking free space tree [5/8] checking fs roots [6/8] checking only csums items (without verifying data) [7/8] checking root refs [8/8] checking quota groups skipped (not enabled on this FS) found 539572510720 bytes used, no error found total csum bytes: 391171280 total tree bytes: 1112637440 total fs tree bytes: 493502464 total extent tree bytes: 156663808 btree space waste bytes: 189219902 file data blocks allocated: 16886634491904 referenced 482911248384 Output of fdisk -l /dev/sdc1 Disk /dev/sdc1: 232.88 GiB, 250058301440 bytes, 488395120 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Output of fdisk -l /dev/sdf Disk /dev/sdf: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors Disk model: WD Blue SA510 2. Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytesdiagnostics-20250624-1557.zip