Your First NAS: What It's Actually For

A NAS is a small computer with disks in it that serves files over your network. The reason to want one is unglamorous and real: instead of photos on a phone, documents on a laptop and videos on an external drive that is never plugged in, there is one place that holds everything, that every device can reach, and that does not belong to a subscription you might stop paying.

The first thing worth getting straight is what it does not do. A NAS is not a backup. It is primary storage with a network port. If you move your only copy of something onto it, you have changed where the single point of failure lives, not removed it. A NAS becomes part of a backup strategy when something copies data off it, to an external drive you rotate or to a cloud target, which is the 3-2-1 rule applied to the box.

The second is that RAID is not a backup either, and this trips up more people than anything else. Mirroring or parity across disks means the array survives a drive dying, which is useful because drives do die. It does nothing about a file you deleted, a sync that propagated corruption, ransomware encrypting the share, a failed controller writing garbage, or the house flooding. RAID buys uptime, not safety.

With that settled, the choices get simpler. Decide capacity by what you have now plus a few years of growth, and prefer fewer larger drives to many small ones, since every bay you fill costs power and noise. Buy drives intended for continuous operation and, if you can, from more than one batch, so that two disks bought together do not fail together. Two bays with mirroring is a sensible starting point; more bays matter mainly if you want parity with capacity efficiency.

For the box itself, the ready-made units from the established vendors are the quickest route and come with a usable interface, mobile apps, and the update cadence someone else maintains. Building your own with TrueNAS or Unraid on old hardware costs less and teaches more, at the price of being the person responsible when it misbehaves. Either is fine; the wrong choice is the one you will not keep maintained.

Two setup decisions pay off for years. Do not expose it to the internet. Remote access through a VPN such as WireGuard or Tailscale gives you your files from anywhere without putting a file server in front of the entire internet, and it removes most of the urgency from patching. And turn on whatever snapshot feature the system offers, scheduled daily, because snapshots are what turn "I overwrote the file" from a loss into an inconvenience.

The app catalogue is where enthusiasm usually goes, and it is worth resisting at first. Get storage, sharing, snapshots and an off-box backup working and boring. Media servers, photo libraries and the rest are easy to add later, once the thing underneath them is something you actually trust.