DSM 7.3 third-party drive policy; verify exact MPN
DS925+ + 3 × 12TB IronWolf
A checked starting combination targeting about 24TB usable with shr / raid 5-style single-drive redundancy.
Lowest checked total$1,734.96B&H + Amazon
Lowest one-store total$1,839.69Amazon
Approx. usable24TB
Checked value$72.29/TB
What the bundle contains
Capacity and redundancy
The three-drive pool can continue after one drive fails and leaves one bay open; RAID is not a backup.
Approximation: $(3 - 1) × 12TB = 24TB$. Filesystem formatting, system partitions, snapshots, and RAID implementation reduce displayed free space.