What is RAID?
RAID = multiple drives working together for speed or protection. Mirroring copies data across drives. Striping splits data across drives for faster reads. Parity uses math to reconstruct lost data.
RAID 0: Speed (no safety)
Combines 2x4TB drives into 1x8TB. Speed: 2× faster reads/writes. Safety: ZERO — one drive fails, all data gone. Use for: video editing scratchpads, temporary projects. Never for important data.
RAID 1: Safety (no speed)
Mirrors 2x4TB drives (one copies the other). Safety: one drive fails, other keeps working. Speed: same as single drive (no improvement). Use for: critical backups, business data, archives.
RAID 5: Both (requires 3+ drives)
Stripes 4x4TB drives + parity = 12TB usable + 1 drive failure protection. Speed: 3× faster than single drive. Safety: one drive fails, rebuild from parity. Use for: NAS systems, media servers, business storage.
RAID 6: Maximum safety
Like RAID 5 but TWO drive failures allowed. 4x4TB = 8TB usable. Slower writes than RAID 5 (double parity calculation). Use for: enterprise, irreplaceable data, large arrays (8+ drives).
RAID setup steps
1. Install matching drives (same size/model recommended). 2. Connect to NAS (Synology, QNAP) or PC with RAID controller. 3. RAID software initializes array (1-2 hours). 4. Format filesystem (NTFS, ext4). 5. Start using. RAID rebuild on failure takes hours depending on drive size.