Use the matrix
Compare capacity and tolerance before opening the exact array planner.
Reference matrix
Compare layouts with the assumptions held constant.
Each column uses equal-size drives and a 10% planning reserve. Use the resulting capacity view alongside the expansion, compatibility, and recovery rules for the chosen platform.
Calculate an exact array shape →| Layout | Fault tolerance | 4 × 8 TB | 6 × 12 TB | 8 × 16 TB | Planning note |
|---|---|---|---|---|---|
| One drive in a two-drive pair | 7.2 TB6.5 TiB after 10% reserve | 10.8 TB9.8 TiB after 10% reserve | 14.4 TB13.1 TiB after 10% reserve | Simple redundancy with one data-drive equivalent. | |
| One drive | 21.6 TB19.6 TiB after 10% reserve | 54.0 TB49.1 TiB after 10% reserve | 100.8 TB91.7 TiB after 10% reserve | Single parity with higher capacity efficiency. | |
| Two drives | 14.4 TB13.1 TiB after 10% reserve | 43.2 TB39.3 TiB after 10% reserve | 86.4 TB78.6 TiB after 10% reserve | Dual parity with an additional capacity cost. | |
| One drive per mirror pair | 14.4 TB13.1 TiB after 10% reserve | 32.4 TB29.5 TiB after 10% reserve | 57.6 TB52.4 TiB after 10% reserve | Mirrored pairs with roughly half of raw capacity usable. | |
| One drive | 21.6 TB19.6 TiB after 10% reserve | 54.0 TB49.1 TiB after 10% reserve | 100.8 TB91.7 TiB after 10% reserve | Single-parity ZFS vdev planning model. | |
| Two drives | 14.4 TB13.1 TiB after 10% reserve | 43.2 TB39.3 TiB after 10% reserve | 86.4 TB78.6 TiB after 10% reserve | Dual-parity ZFS vdev planning model. |
Then verify
Check the actual NAS, controller, ZFS vdev, SHR, or Unraid expansion rules before buying drives.
Continue
Build a storage baseline →