Earlier, I accidentally assigned two SSDs to the existing cache pool.

In oder to correct that and to remove the wrong SSDs I then went to “New Configuration” and left the array unchanged.

I was able to define other pools (boot and temp), but when defining the cache pool, the following message appears:

Do not use user-shared names

What am I doing wrong?

tower-diagnostics-20260911-2033.zip

Edited September 11Sep 11 by EdgarWallace

you have inadvertently created a share by the name "cache" you need to go into the /boot/config/shares folder and remove it/any that are not actually shares

Thanks @MowMdown

There is no share with the name "cache" but both drives are showing up in Unassigned Devices.

Just checked - you are right there is /boot/config/shares/cache.cfg existing. So just deleting it?

That might not be enough! You first need to check that you do not have a folder called ‘cache’ on any of your array drives or pools as Unraid automatically creates a share with the same name as any folder at the top level of an array drive or pool. You also need to check you do not have any docker container with drive mapping referencing such a folder or it will keep re-appearing when you start the container.

I had AppData, Domains, and System on the cache drive, and I hope the data is still there.

Just in case, I do, of course, have a backup of the cache data.

2 hours ago, EdgarWallace said:

Just checked - you are right there is /boot/config/shares/cache.cfg existing. So just deleting it?

Like Itimpi said, you might have something writing to /mnt/user/cache which would have created a folder named cache on the system somewhere.

However to be safe disable docker service from the settings menu so you can at least get the array started for now. make sure no other folders named cache exist and if they do make sure you dont accidentally delete any data before removing/renaming them.

I disabled both docker and VM services. I was able to start the array and the issue now is the following:

Unmountable disk present:
Cache • Samsung_SSD_990_PRO_with_Heatsink_2TB_S73HNJ0Y300354V (nvme0n1)
Cache 2 • Samsung_SSD_990_PRO_with_Heatsink_2TB_S73HNJ0Y304753B (nvme1n1)

Is there any way to prevent formatting? I am sure that nothing happened to the file system on any of the drives.

Please post the diagnostics after array start

Sorry, forgot that. Posted below

tower-diagnostics-20260912-0847.zip

Pool appears to have another member; post the output from

zpool import

root@Tower:~# zpool import
  pool: cache
    id: 16121631689107972322
 state: UNAVAIL
status: One or more devices contains corrupted data.
action: The pool cannot be imported due to damaged devices or data.
   see: https://openzfs.github.io/openzfs-docs/msg/ZFS-8000-5E
config:

        cache                    UNAVAIL  insufficient replicas
          mirror-0               ONLINE
            nvme0n1p1            ONLINE
            nvme1n1p1            ONLINE
          mirror-1               UNAVAIL  insufficient replicas
            sdb1                 UNAVAIL
            2689372608096457617  UNAVAIL

The 2nd mirror has no available device, meaning, unless you can get at least one good device from that mirror, the pool will need to be destroyed and recreated.

Thanks to all of you @itimpi @JorgeB @MowMdown

I am going to recreate the pool with the backup that I am having. Remaining issue is the the message "Started, formatting..." is not going away.

zfs pool status

  pool: cache
 state: ONLINE
config:

	NAME                STATE     READ WRITE CKSUM
	cache               ONLINE       0     0     0
	  mirror-0          ONLINE       0     0     0
	    /dev/nvme0n1p1  ONLINE       0     0     0
	    /dev/nvme1n1p1  ONLINE       0     0     0

errors: No known data errors

zfs pool information

NAME            SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
cache          1.81T  1.95M  1.81T        -         -     0%     0%  1.00x    ONLINE  -
  mirror-0     1.81T  1.95M  1.81T        -         -     0%  0.00%      -    ONLINE        -
    nvme0n1p1  1.82T      -      -        -         -      -      -      -    ONLINE        -
    nvme1n1p1  1.82T      -      -        -         -      -      -      -    ONLINE        -

tower-diagnostics-20260912-1054.zip

14 minutes ago, EdgarWallace said:

Remaining issue is the the message "Started, formatting..." is not going away.

Do you mean in the GUI footer? Did you refresh the page?

In the footer as well as on the main screen. Yes I refreshed the page and was trying a different browser. No change.

Post a screenshot and new diags.

Here you are:

tower-diagnostics-20260912-1150.zip

It might just be a display issue. I copied 2 out of 3 datasets (appdata and domains), and the subsequent check appears to show a 100 % match in the data.

I'll be away for a bit, and I'll reboot the server tonight after the copies are complete and the data has been verified, and then I'll get back to you.

Pool was formatted correctly; it looks like just a display issue with the GUI, but I cannot see what's causing it. I recommend rebooting when you can.

A reboot solved the issue with the GUI. Restarted VM and Docker engine and everything is running well again. Again, thanks to all of you.