File system not available as Device for Snapraid and others

I put a new 12TB HDD into my OMV. The OMV is running a RAID6 and I want to add the new disk as a new Snapraid parity. I formatted it EXT4 and mounted it. During the mount process I had an error but after a restart the disk seems to be mounted (Seagate12TB).

If I try to put this device as Snapraid device I cannot chose it from the list.

The error I got during mount was related to the disk ID. I am not able to access the first entry in this list via console as non-root. But accessing it via the disk-by-label is possible. Maybe this is related to the problem now. Maybe not. Thanks for your help.

Unmounting and re-mounting the disk brings the following error.

Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C.UTF-8; mount '/srv/08993d3c-3bc1-4cf6-9d3f-724e25653c3f' 2>&1' with exit code '32': mount error(2): No such file or directory Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)

After some further searching I did two things:

- I wiped and formatted the disk with another file system (EXT3) and then again with EXT4.

- I deleted some entries from my /etc/fstab

- I removed some remote file systems via the GUI

I am not sure which one was usefull, but now it works.