2026 NAS Buying Guide: 2, 4 or 6 Bays for Homelab

Choosing the right number of drive bays for a NAS isn’t a matter of taste, but of applied mathematics to your digital life. In 2026, the line between personal storage and server infrastructure has blurred. A simple 2-bay NAS might suffice for archiving photos, but it will quickly become a bottleneck if you host a 4K media server, a Proxmox cluster, or a centralized backup system for a small group. The decision between 2, 4, or 6 bays rests on three pillars: fault tolerance (RAID), simultaneous access throughput, and headroom for growth without having to migrate your data. Ignoring these criteria often leads to rapid hardware obsolescence, forcing costly and risky migrations.

Why this choice matters (concrete technical criteria)

The number of bays directly determines your redundancy strategy and write performance. With a RAID 1 (mirror) configuration on two drives, you lose 50% of the raw capacity. To gain write performance, you need to move to RAID 5 or 6, which requires a minimum of three or four drives, respectively. On a 2-bay NAS, you are often limited to RAID 1, which is safe but inefficient in terms of space utilization.

Scalability is the second critical factor. A 4-bay NAS offers significantly greater flexibility: you can start with two drives in RAID 1 for security, then add two more to form a RAID 5, effectively doubling your usable capacity while increasing fault tolerance. 6-bay models allow you to go further with RAID 6 (tolerance for two simultaneous drive failures), which is essential for irreplaceable data. Finally, CPU power and RAM quantity are often correlated with the number of bays. 4- and 6-bay chassis generally house more powerful processors and allow for more than 8 GB of RAM, which is crucial for ZFS caching or running multiple Docker containers.

Buying criteria

Before looking at specific models, define your total budget including the drives. NAS units are often sold “bare,” which may seem attractive, but NAS drives (such as WD Red Plus or Seagate IronWolf) represent 60 to 80% of the total cost. Check drive compatibility with the NAS operating system, especially if you plan to use ZFS (TrueNAS or Synology). For self-hosting, prioritize open models or those with an unlocked BIOS if you intend to install Proxmox or a custom Linux system. Network connectivity is also decisive: 2.5GbE has become the standard for small home networks, allowing you to saturate mechanical drives, while 10GbE is reserved for large volumes or intensive virtualization.

Presentation of the 3 recommended products

Synology DiskStation DS224+ (2 bays)

The DS224+ is the current reference for beginner or intermediate users who want reliability without complexity. It is equipped with an Intel Celeron J4125 processor, an older but robust quad-core chip, and supports up to 16 GB of RAM. Its main advantage is the DSM operating system, considered the most intuitive on the market. For a homelab, it excels in managing Docker packages via Docker Compose and integrates natively with Home Assistant via the official add-on. The limitation remains raw storage capacity: with two 18 TB drives, you will only have 18 TB of usable space in RAID 1. This is ideal for a family media library, Time Machine/Windows backups, and a few lightweight services.

QNAP TS-464 (4 bays)

The TS-464 is a monster of versatility. It integrates an Intel Core i3-N305 (8 cores) and features two M.2 NVMe slots for SSD caching or fast storage. This model is particularly suited for advanced users who want to virtualize. With 16 GB of upgradable RAM, it can host multiple virtual machines under QTS or even be reflashed with Proxmox VE for pure hardware management. The dual 2.5GbE ports allow for bonding or network traffic separation. It offers total flexibility: start with 2 drives in RAID 1, then expand to 4 in RAID 5 or SHR-2 (for QNAP users). It is the ideal choice for a heavy media server (Plex/Jellyfin with hardware transcoding) and a Docker container cluster.

TrueNAS Scale 15 (6 bays - Custom or pre-assembled chassis)

Here, we are talking about a different approach. Instead of recommending an “off-the-shelf” NAS, we recommend buying a 6-bay chassis (such as a Fractal Design Node 804 or a dedicated chassis like those from SilverStone) and installing a motherboard compatible with TrueNAS Scale. This solution is for those who want total control. TrueNAS Scale uses ZFS, the most robust file system for data integrity. With 6 bays, you can configure a RAID-Z2 (equivalent to RAID 6), tolerating two drive failures while using 2 drives for parity. This is the ultimate solution for long-term archiving, database backups, and development environments. The learning curve is steeper, but the stability is unmatched.

Comparison table

Criteria	Synology DS224+ (2 bays)	QNAP TS-464 (4 bays)	TrueNAS Scale (6-bay custom)
Drive Bays	2	4	6
Processor	Intel Celeron J4125	Intel Core i3-N305	Variable (e.g., i5-12400)
Max RAM	16 GB	32 GB	Depends on motherboard
Optimal RAID	RAID 1 (Mirror)	RAID 5 / SHR-2	RAID-Z2 (ZFS)
Capacity Loss	50%	33% (RAID 5)	33% (RAID-Z2)
Network Ports	1x 2.5GbE	2x 2.5GbE	2x 2.5GbE or 10GbE
OS	DSM (Proprietary)	QTS (Proprietary)	Linux Debian (Open Source)
NAS Price (bare)	~€250	~€450	~€300-500 (chassis+MB)
Drive Price (2x16TB)	~€600	~€900	~€1350
Estimated Total	~€850	~€1350	~€1700+

Note: Prices are indicative and vary according to promotions. Drives are calculated for high-capacity 16 TB models.

Use cases

If you are an individual with less than 5 TB of data to protect, family photos, and a few movies, the Synology DS224+ is the most stress-free choice. It requires little maintenance and offers a smooth user experience. You can find this type of configuration on Amazon to simplify logistics.

For tech enthusiasts, streamer gamers, or those hosting a Minecraft server, a Docker container cluster, or a Plex server, the QNAP TS-464 is the perfect balance point. Its CPU power allows for effortless video transcoding, and its 4 bays offer enough headroom to grow. Check out /comparatifs/meilleur-nas-2-baies-2026/ if you are still hesitating on 2-bay models, but know that the jump to 4 bays changes the game.

Finally, for professionals, system architects, or those managing critical data (wedding photos, customer data, legal archives), the 6-bay TrueNAS solution is indispensable. The RAID-Z2 redundancy and ZFS data integrity are worth the additional investment and management complexity.

Pitfalls to avoid

The first pitfall is underestimating power consumption. A 6-bay NAS with spinning drives can consume between 50 and 100 Watts at idle, compared to 20-30 Watts for a 2-bay unit. Over a year, this represents a significant difference on your electricity bill. The second pitfall is buying “desktop” drives (such as WD Blue) instead of NAS drives (WD Red Plus, IronWolf). The latter are designed to vibrate less and run 24/7, which significantly increases their lifespan in a RAID environment. The third pitfall is neglecting the 3-2-1 backup rule. A NAS is not a backup. If you have a RAID 1, a logical corruption or a fire will destroy both copies. Always keep an external copy (cloud or disconnected hard drive).

Verdict

There is no universal “best” NAS, only the best NAS for your current data volume and your tolerance for complexity. For the majority of modern households in 2026, the jump to a 4-bay NAS like the QNAP TS-464 offers the best price/performance/flexibility ratio. It allows you to start small and grow without changing the chassis. If simplicity is your motto, stick with the 2-bay Synology. If data is king, invest in the 6-bay TrueNAS. Whatever your choice, make sure to size your bays for the next 5 years, as drive prices and the complexity of data migrations only continue to increase.