Backing up a media library calls for different priorities than streaming one. A NAS bought to archive years of photos and video needs bay count, RAID redundancy headroom, and raw capacity more than it needs a fast CPU for transcoding — those are two different jobs that happen to run on similar-looking hardware. For most households with a growing photo and video archive, a 4-bay NAS running a redundant RAID configuration, sized with real headroom above your current library, is the right starting point rather than a 2-bay box that looks like enough today.
What to look for
- Bay count with room to grow. Four bays let you run redundant RAID and still have expansion room; two bays leave no path forward once the library grows past current capacity.
- NAS-rated hard drives, not desktop drives. Drives built for 24/7 multi-bay operation handle vibration and continuous workload in ways standard desktop drives are not rated for.
- RAID level appropriate to your risk tolerance. More redundant configurations sacrifice some usable capacity for protection against multiple simultaneous drive failures.
- An actual offsite or cloud copy of anything irreplaceable. RAID protects against a drive dying; it does nothing against theft, fire, ransomware, or accidentally deleting the wrong folder.
Top picks for media backup
| NAS |
Bays |
Max raw capacity (approx.) |
RAID support |
Best for |
| Synology DS923+ |
4 |
Multi-bay, expandable |
Synology Hybrid RAID, RAID 1/5/6 |
Households wanting polished setup software |
| QNAP TS-464 |
4 |
Multi-bay, expandable |
RAID 0/1/5/6/10 |
Buyers wanting more hardware for the money |
| UGREEN NASync DXP4800 |
4 |
Multi-bay, expandable |
Multiple RAID levels |
Budget-conscious first-time NAS buyers |
| Asustor Lockerstor 4 |
4 |
Multi-bay, expandable |
RAID 0/1/5/6/10 |
Balanced feature set and price |
| TerraMaster F4-424 |
4 |
Multi-bay, expandable |
RAID 0/1/5/6/10 |
Value-focused hardware specs |
Drive capacity, current pricing, and exact RAID options vary by configuration — check the current model page rather than assuming last year's specs still apply.
How many bays and how much RAID overhead
A 4-bay NAS running RAID 5 or its vendor-specific equivalent gives you the capacity of three drives with one drive's worth of redundancy — meaning any single drive can fail without losing data. Two bays only really support mirroring, which halves your usable capacity for the same protection level and leaves no expansion path once you fill it. If your media library already exceeds a few terabytes or grows steadily every year, size the NAS for where the library will be in two to three years, not where it is today.
Common mistakes
- Buying a 2-bay NAS for a library that is clearly still growing. It works at first, then forces an awkward migration to a bigger box once you run out of room.
- Treating RAID as your backup. RAID protects against drive failure specifically. It does not protect against ransomware, fire, theft, or accidental deletion — keep a separate copy of anything irreplaceable.
- Using standard desktop drives in a multi-bay enclosure. They are not rated for the vibration and continuous operation of running alongside several other drives around the clock.
- Underbudgeting for drives relative to the enclosure. The NAS box itself is often the smaller line item; several NAS-rated drives at meaningful capacity usually cost more than the enclosure.
FAQ
How many bays do I need to back up a media library?
Four bays is a comfortable starting point for most growing photo and video libraries, since it allows redundant RAID with real capacity and future expansion room.
Is RAID the same as a backup?
No. RAID protects against a drive failing. A genuine backup means a separate copy, ideally offsite or in the cloud, protecting against fire, theft, ransomware, and accidental deletion.
Do I need NAS-rated hard drives specifically?
For always-on multi-bay use, yes. NAS-rated drives are built for continuous operation and the vibration of running alongside other drives, which shortens the life of standard desktop drives.
Can I add capacity later without starting over?
Often yes, depending on the NAS and RAID level, through drive swaps or expansion units. Buying a model with spare bays up front makes this meaningfully easier.
Where to go next
If you are deciding between free NAS software and a polished commercial platform, TrueNAS vs Synology in 2026 covers that tradeoff directly. Pair your NAS with the right always-on hardware in the best mini PCs for a home server in 2026, and make sure the rest of the house can actually reach it with the best mesh Wi-Fi for large homes in 2026.