Hidden talents and hidden decisions: make your choice

This is one of the biggest investments you’re going to make in your infrastructure, so be aware of every variable before buying

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If you mostly want a destination for computer backups, or a large storage space to share files across a network, almost any NAS drive will do the job - but we can do better than that. The best NAS devices offer more speed, more features, or an upgrade path to support your growing needs. Here’s how to find your ideal NAS.

How many bays do I need?

We don't recommend single-bay enclosures as they offer no redundancy for your data - if their single disk fails, everything on it is likely to be gone for good. At a minimum, get a two-bay device, and create a RAID1 array. This mirrors your data between both drives, so if one fails, you'll still have a copy on the other one. Don't be tempted by other configurations such as JBOD or RAID0: while they give you more space, they don't have any fault tolerance.

A four-bay NAS enclosure is more versatile. Even if you only start with two disks in a RAID1 array, you'll have two free slots to add capacity later. With three or four disks you can set up (or migrate an existing RAID1 array to) RAID5, which offers a better balance of capacity and data security. In RAID5, the space of only one disk is used for data redundancy, so if you use four 4TB disks you'll get 12TB of usable space, and if a single disk fails your data will still be safe.

For really mission-critical data, consider RAID6. This can survive two drives failing simultaneously, but it uses more storage space - in the example above you'd get only 8TB of usable storage. Whichever you choose, minimise the risk of data loss by replacing any failed drive immediately.

It’s increasingly common to find flash-only NAS enclosures, or disk-based devices that also have M.2 slots. These support NVMe SSDs, which offer faster storage, or caching for the main disks, or both. In this test, TerraMaster’s F4 SSD and QNAP’s HS264 are flash-only, while several enclosures combine disk and flash.

What connections do I need?