Decision order
- Keep the current layout
- Add equal-size drives to empty bays
- Replace every drive in the current NAS
- Migrate to a larger enclosure
Important: Expansion and mixed-drive behavior vary by vendor. This tool uses generic equal-size RAID math. Verify the official compatibility list and expansion procedure, and complete an independent backup before changing an array.
Migration safety
Temporary storage is planned at 120% of current data. It is separate from the existing 3-2-1 backup. Never begin drive replacement without a tested independent copy.