Hardware - Start small and cheap. If you have it already use it. build it out as you need and understand it.
Software (OS) - Debian based perhaps. Docker probarbly.
Utilities - What would you like to do today? pick one, Pihole is useful.
Once you get something working for yourself, you’ll start to build on that knowledge.
Above all be brave and be curious.



Frugal and recycled. Using a mix of old disks in OMV8 with a mergerfs array, suprisingly they amounted to 20TB, so saved a few bob.
If a disk fails in Mergerfs you loose the data on that disk only and not the array as you would with a pure jbod array.
There is a remove disk utility in the OMV8 mergerfs plugin that allows the data from a failing disk to be copied back to the array, if enough space is available, retaining the data from the failing disk. The disk can then be physically removed. If the array is short on space, add a disk to expand the array before removing the failing disk.
I’ve only ever used it with a failing disk, not a failed disk, I would guess that a backup would be required in that case.
The same applies to mergerfs outside of OMV8, this was easier for me.