A NAS ("Network Attached Storage") sounds like a mysterious appliance, but it's really just a computer whose only job is holding files and sharing them over your network. A Synology or QNAP box is a small, pre-built PC running storage software — if you've got an old desktop gathering dust, it can do the exact same job for the price of some hard drives. This guide assumes you've never done anything like this before.
● no prior server experience assumedOn this page
You almost certainly already have most of this. Nothing here needs to be new or fast.
| Component | Bare minimum | Ideally |
|---|---|---|
| Computer | Anything from the last ~10 years that still boots | Has a couple of free internal drive bays |
| RAM | 4 GB (OpenMediaVault) | 8 GB or more — TrueNAS SCALE's ZFS filesystem officially wants at least 8 GB |
| Storage drives | 2 drives, any capacity | 3+ drives, matching capacity — mismatched sizes waste capacity down to the smallest drive on everything except Unraid |
| Network | Built-in Ethernet port | Gigabit Ethernet, connected by cable — not Wi-Fi |
| USB stick | 8 GB, for the installer (or permanently, if you choose Unraid — see below) | — |
| UPS (battery backup) | Optional | Cheap insurance against a mid-write power cut corrupting the pool — a real risk, though somewhat less so on TrueNAS's copy-on-write ZFS than on OpenMediaVault or Unraid |
This is the software that turns a bare PC into a NAS. All of these do the core job (storing and sharing files) well. Your data isn't locked into a proprietary format, but switching between them later isn't a free move either — a TrueNAS ZFS pool only reads on another ZFS system, and moving between any of these generally means copying your files off, reformatting, and copying them back, which takes spare storage you probably don't have as a beginner. So it's worth a few minutes' thought now rather than "just pick one."
| OS | Cost | Best for |
|---|---|---|
| TrueNAS SCALE | Free | The most "proper" option — built on ZFS, a filesystem that detects silent data corruption. Slightly more technical setup than the others, and wants more RAM (see the table above). |
| OpenMediaVault | Free | The simplest web interface of the free options — a good first choice if TrueNAS feels like a lot. |
| Unraid | Paid (licence plans — check current pricing before committing) | The friendliest UI, and unlike the others it lets you mix drives of completely different sizes in one pool — good if your "old PC" drives don't match. Unlike the others, it also boots permanently from the USB stick itself rather than installing to an internal drive — budget a stick you're happy to leave plugged in for good. |
| Windows file sharing | Already own it | Works in a pinch, but it's not really a NAS — no drive redundancy, no snapshots, and Windows updates will happily reboot your "server" mid-week. Fine for testing, not for anything you'd be upset to lose. |
The install process will erase the drive it's installed to. If there's anything on this PC you still want, copy it off first.
Install as many hard drives as you have bays for. One small drive (even an old laptop SSD) can be set aside just for the OS itself, separate from the drives holding your actual files.
A NAS depends on network speed. Wi-Fi works but is slower and less reliable for large file transfers — use a network cable if there's a router or switch anywhere nearby.
Download your chosen OS's installer image (an .iso file) and write it to the USB stick with a free tool like balenaEtcher or Rufus — plain drag-and-drop copying won't make it bootable.
Restart the PC and tap the key that opens its boot menu during startup — commonly F12, F2, Esc, or Del (it's usually shown briefly on screen). Choose the USB stick instead of the internal drive.
Point it at the small drive you set aside for the OS in Step 2 — not your storage drives, which you'll set up separately next. The wizard will ask for a hostname and an admin password; write the password down somewhere. Exception: if you're installing Unraid, there's no separate OS drive to pick — it installs to, and boots from, the USB stick itself every time the machine starts, so just leave the stick plugged in permanently.
After it reboots, the NAS will print an IP address on its own screen (something like 192.168.1.50). From any other computer's browser, go to that address to open the web admin panel — from this point on, you never need a monitor or keyboard on the NAS itself.
This is the step that scares most beginners, but the underlying idea is simple: instead of using each drive separately, you combine them into a pool that shares data across every drive in it — so if one drive dies, the others can rebuild what was lost.
The web interface will offer a few pool layouts. As a beginner with 2–3 similar-sized drives, a straightforward mirror (an exact copy kept on two drives) or a single-parity pool (one drive's worth of capacity spent on recovery data) are both reasonable starting points — the wizard will explain the trade-off in capacity for each option you pick. One thing worth knowing: with single-parity on larger drives (a few TB and up), rebuilding after a failed drive puts hours of sustained read load on your remaining drives, and a second failure during that window loses the whole pool — a mirror, or double parity if your OS offers it, is the safer choice once drives get large.
Turn on SMART monitoring and scheduled scrubs if your OS offers them (all three do), and set up email alerts for pool health. Without them, a pool that's already lost one drive and is quietly running on redundancy alone can go unnoticed for months — until a second drive fails and takes the data with it.
In the web admin panel, create a share (usually called an "SMB share") on top of your storage pool and give it a name, like media or backups. You'll also need to create at least one user account on the NAS itself and grant it access to the share — this account is separate from any login on your own computer, and forgetting this step is the most common reason people hit "access denied" on their first attempt.
Open File Explorer, type \\NAS-IP-ADDRESS\sharename into the address bar, and enter the NAS username/password you just created. Right-click it and choose "Map network drive" to make it appear as its own drive letter every time.
In Finder, choose Go → Connect to Server and enter smb://NAS-IP-ADDRESS/sharename.
In most file managers (Nautilus, Dolphin), choose "Connect to Server" or "Other Locations" and enter smb://NAS-IP-ADDRESS/sharename the same way as on a Mac. To mount it permanently at boot instead, add a line to /etc/fstab using the cifs filesystem type.
A NAS that just stores files is already a complete, useful project — you don't need to do any of this. But most of these operating systems can also run apps (often via Docker containers) once you want more:
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