I had it configured and working well but we had an electrician around to test the circuit breakers, unfortunately I didn’t have my server plugged in to the ups.
When I booted it back up the Raspberry Pi was trying to boot from the backup drive instead of the nethserver SSD (if I unplugged it and rebooted it worked fine but if I plugged it in again it would get reassigned and cause the Raspberry Pi to crash).
I decided I would fix it the next week (and completely forgot about until I tried to restore a backup).
So Ive fixed the mounting and set fstab correctly on reboot the drive shows up in the storage part of settings on cockpit Im able to erase and remount in via nethgui or cli (ive got it mounted to /mnt/backup) I can write to it and on reboot it mounts fine and is still writable.
@Shane_Treweek… no commas or carriages return in your message. Would you please kindly… edit your message and add a bit more info?
What your RasPi sais if you plug the disk?
Receives any mountpoint?
Which is the filesystem?
Did you check that the content is browseable from another installation (depending on the FS)
Sorry for that I was quite tired when I typed that (need to remember to check before posting ) apon re-reading my post I couldn’t fully understand what I wrote so i started the post again.
It works fine now (mounting and on boot no conflicts)
it’s mounted automaticaly at /mnt/backup
it’s formatted to EXT4
yes I booted a live cd (well usb) ubuntu on my mac plugged the drive in and was able to write to the hdd
also I’ve it helps
# ls -l /mnt/backup
total 16
drwxrwxrwx 2 root root 16384 Sep 3 22:24 lost+found
I origonaly had ext4 in the last line UUID=70a6f1cc-640a-478e-8821-7257f2c348f3 /mnt/backup ext4 auto defaults,noatime,nofail 0 2
but when I ran mount -a it would give an error about config not being correct
) apon re-reading my post I couldn’t fully understand what I wrote 
so i started the post again.