This whole process is scary. Essentially to expand a RAID6 capacity either requires replacing every drive (full rebuilds) and then expanding the capacity... or just backing everything up, swapping all drives, building a new RAID6 and copying the data back.
The second option is safer... except whilst doing it, the data will only exist in one place (well, the old drives in theory still have the data, but in practise who knows).
Upgrading my NAS to 24TB this evening.
This whole process is scary. Essentially to expand a RAID6 capacity either requires replacing every drive (full rebuilds) and then expanding the capacity... or just backing everything up, swapping all drives, building a new RAID6 and copying the data back.
The second option is safer... except whilst doing it, the data will only exist in one place (well, the old drives in theory still have the data, but in practise who knows).