An update on my side:
I installed Armbian and installed openmediavault successfully on a spare SD. Using the openmediavault UI, I formatted my new harddisk with the BTRFS filesystem. Everything seems fine using openmediavault. it lists my disk using fdisk -l.
Then got back to the Nextcloudpi image. Even with a formatted disk, it still does not detect my harddisk. I cannot mount it, I cannot (re)format it using the NCP wizard.
Using this image I cannot find my harddrive with:
fdisk -l
I just lists the SD-card and zram0 and zram1 disk
ls -l /dev/disk/by-uuid/
only lists …/…/mmcblk1p1 which is my SD-card.
I’m just a user… so stuck at the moment.
Maybe edit /etc/fstab to get it mount my hdd?