What is a NAS and do I actually need one?
A small always-on computer full of drives that everything in the house can reach. What it genuinely solves, what it does not, and the honest test of whether you are the household for one.
- Difficulty
- intermediate
- Time
- 30 min
- Read
- 4 min
Short answer
A NAS is a network-attached storage box: two or more drives in an appliance that sits by the router and serves files to every device in the house. It is worth it if several people need the same large library, if you want backups to run without plugging anything in, or if you want to host your own photo library instead of paying a subscription. It is not a backup by itself, and for one laptop an external drive plus cloud storage is far cheaper.
The NAS is over-recommended online, because the people who write about them enjoy them. The question is not whether it is capable — it is — but whether your household has the problem it solves.
Step by step
- Establish what it actually is.A low-power computer with a simple web interface and bays for two to four drives, connected to your router by cable. Devices see it as a network drive. It runs continuously, which is the point: nothing has to be plugged in for a backup to happen.
- Test whether you have the problem.Do several people need the same large files? Do you have more data than fits comfortably on a laptop? Do backups fail because nobody plugs the drive in? Do you want to leave a photo subscription? Two or more yes answers, and it earns its place. One or fewer, and it will be an expensive hobby.
- Understand what the drive redundancy does and does not do.A two-drive NAS mirroring its drives survives one drive failing without downtime. That is uptime, not backup. Delete a file and it disappears from both drives instantly; ransomware encrypts both. A NAS still needs its own backup, to an external drive or to a cloud service.
- Price it honestly.The enclosure, plus drives — usually the larger cost — plus a backup for the NAS itself, plus electricity for a device that runs all year. Compare it against several years of an external drive and a cloud subscription before deciding.
- Decide between an appliance and building one.A ready-made NAS from an established manufacturer gives you working apps, phone access and updates, at a price. A repurposed old computer running free NAS software is cheaper and is a project you will maintain forever. Be honest about which you want.
- Check the features that actually matter.Snapshots, so a mistake or an encryption does not destroy the previous version. Its own backup to an external drive or cloud. A published record of security updates, because it is a computer exposed to your network. Enough processing power if you intend to stream video that must be converted on the fly.
- Be careful about reaching it from outside.Remote access is the main attraction and the main risk. NAS devices exposed directly to the internet have been a repeated target of automated attacks. Use the manufacturer's own relay service or a private network back to the house, keep it updated, and never forward ports to it casually.
- Plan the drives.Buy drives rated for continuous operation rather than desktop drives; they are specified for the vibration and duty cycle. Buying two drives from different batches reduces the chance of both failing at once.
Alternatives
- External drive plus cloud storage: Covers most households completely: a local copy for speed and an offsite copy for disaster. Cheapest, simplest, and nothing to administer. Requires someone to plug the drive in.
- A drive plugged into the router: Many routers share a USB drive to the network. Slow, limited and with no redundancy or snapshots, but free if you already have both and adequate for occasional shared files.
- Two-bay NAS from a major manufacturer: The usual sweet spot: mirrored drives, phone apps, its own backup to cloud, low power. Costs several hundred pounds with drives and needs occasional attention.
- An old computer running NAS software: Very capable for the money and educational. It uses more electricity, takes more space, and depends on you to maintain it — which is fine if that is the appeal and a liability if it is not.
Questions people ask
Can a NAS replace my cloud subscription?
For photo libraries, largely yes — the mainstream NAS makers ship photo apps with phone upload. You take on the responsibility that the service used to carry: updates, backups of the NAS itself, and remote access done safely.
Is a NAS a backup?
No, on its own. It is a shared store with good availability. The moment it holds the only copy of something, it is a single point of failure with a fan in it.
Does it need to be near the router?
Connected to it by cable, so effectively yes. Wired is not optional for a NAS — Wi-Fi makes it slow and unreliable for exactly the tasks people buy one for.
How much electricity does it use?
A small two-bay unit with drives spinning down when idle uses modest power continuously. It is not a large sum over a year, but it is not nothing, and it is a real difference from a drive that is unplugged most of the time.