Build your first NAS

A NAS is just a computer whose only job is to hold your files and hand them out over the network. That is the whole idea. Everything below is about making that job cheap, quiet, and reliable enough that you stop thinking about it. Here is the build, in the order the decisions actually matter.

1. Decide what it is really for

Be honest about the workload before you spend a cent. Three photos-and-documents users need almost nothing. A household streaming 4K movies to three TVs, running backups every night, and hosting a few containers needs real hardware. Write down the two or three things you actually want it to do. Every later choice falls out of that list.

The most common first-NAS job is simple: one safe copy of everything, reachable from any device, plus a target for automatic backups. If that is you, resist the urge to over-build.

2. Pick DIY or prebuilt

There are two honest paths and the right one depends on your appetite, not your budget.

• Prebuilt (Synology, QNAP, UGREEN, Asustor). You get a small box, a polished app, and a support line. You pay a premium and you accept their ecosystem. This is the right call if you want it to work like an appliance and never touch a terminal.
• DIY (a mini PC or small server plus your own drives). More control, more capacity for the money, and no vendor lock-in, at the cost of doing the setup yourself. A compact mini PC with a couple of drive bays, or a small tower, runs free NAS software beautifully.

Neither is wrong. If you already enjoy tinkering, DIY pays off. If you do not, a prebuilt is not a compromise, it is the correct tool.

3. Choose the drives (this is the part people get wrong)

Storage is where a NAS lives or dies, so slow down here. Two rules cover most mistakes:

• Buy CMR, not SMR. SMR drives can stall during a RAID rebuild - exactly when you need them most. The catch is that manufacturers hide which is which. The full CMR-vs-SMR breakdown and a searchable list of which drives are which is what NASdisks exists for; check a model there before you buy it.
• Match capacity to a plan, not a whim. Two large drives in a mirror is a better starting point than four small ones, because it leaves room to grow and keeps power and noise down. Buy drives in a pair or a set so they age together.

Do not buy the cheapest desktop drive on sale. A NAS drive is rated to run 24/7 and to sit next to vibrating neighbours; a cheap desktop drive is not, and the price gap is small next to the cost of losing data.

4. Understand RAID before you rely on it

RAID keeps you online when a drive dies. It is not a backup. Say that twice, because it is the single most expensive misunderstanding in this hobby.

For a first build, a two-drive mirror (RAID 1) or a modern equivalent is plenty: one drive can fail and your data survives. More bays let you use parity layouts that survive a failure while wasting less space, but the complexity climbs. Start simple. What you actually need is the 3-2-1 rule - three copies, two kinds of media, one off-site - and RAID is only part of the "three copies" line.

5. Pick the software

The box is nothing without the OS. The mainstream free choices:

• TrueNAS - rock-solid ZFS storage, huge community, the default serious pick.
• Unraid - flexible, mixes drive sizes, friendly for people who add disks over time (paid, but modest).
• The vendor OS (Synology DSM, etc.) if you bought prebuilt - genuinely good, just theirs.

Any of these will do the core job. Pick one and commit; hopping between them is how weekends disappear.

6. Put it on the network properly

A NAS is only as fast as the link to it. For most homes gigabit is fine, but if you move large files often, a 2.5-gigabit switch and NIC is a cheap, dramatic upgrade, and it is the natural next purchase after the NAS itself. The networking side - switches, NICs, and routers that do not fight you - is covered at HomeSwitches.

Give the NAS a fixed address, keep it on your trusted network, and do not expose its admin panel to the internet. If you want remote access, use the vendor app or a VPN, never a port forward to the management page.

7. Set up backups on day one

The NAS holds the primary copy. It is not the only copy. Before you move your real files onto it, decide where the second and third copies live: an external drive you rotate, another NAS, or a cloud target. Automate it, then test a restore once so you know it works. A backup you have never restored from is a hope, not a backup.

The short version

Decide the job, pick DIY or prebuilt honestly, buy CMR drives sized to a plan, start with a simple mirror, choose one OS and commit, put it on a network that can keep up, and set up backups before you trust it with anything. Do that and your first NAS becomes the boring, dependable box it is supposed to be. When you are ready to pick the exact drives, start at NASdisks; when you are ready to pick the box, start at ServerRigs.