A NAS - a network-attached storage box - is the quiet workhorse of a small office: a shared drive everyone reaches, a place backups land, somewhere the CCTV records. The trouble is the buying advice online is written for home media fans, not businesses, so people end up with a lovely 4K-streaming box that has no real backup and falls over when the team is busy. This is how to pick the right one for work, and which shiny features to ignore.
First, be honest about what you need it for
The biggest buying mistake is shopping by brand before you have decided the job. A NAS for a small business usually does one or more of three things, and each pushes you toward a different size of box. Getting this clear first saves you both from overspending and from the far more common error of under-buying.
If you only need a shared company drive for documents, almost any two-drive business NAS will do. If it is also catching backups from laptops and a server, you want more bays and more space. If it is recording security cameras around the clock, that is a genuinely demanding job that needs a NAS built for surveillance, with the drives to match. We explain the device itself in plain terms in what is a NAS for small business.
The number that actually matters: bays, not headline capacity
Forget the giant terabyte number on the box for a moment. The figure that decides whether your NAS is fit for business is the number of drive bays, because that determines whether you can survive a dead disk and how you grow later.
- •Two bays (entry): fine for a simple shared drive, but you lose half your space to protect against one drive failing. Workable for the smallest offices.
- •Four bays (the sweet spot): the realistic minimum for most businesses - room for resilience and capacity, and headroom to add disks later without buying a new unit.
- •Six to eight bays: for firms with a server to back up, lots of cameras, or large design and media files. Buy here if you expect to grow within three years.
- •A blunt rule: buy one more bay than you think you need today. Filling a NAS is far easier than replacing it.
The features worth paying for
Once the size is right, a handful of business-grade features separate a serious office NAS from a dressed-up home one. These are the things that matter at 9am on a Monday, and the things an auditor or your insurer will ask about.
Look for proper user accounts and folder permissions tied to your Microsoft 365 or Windows logins, so the right people see the right folders. Look for snapshots - point-in-time copies that let you roll a folder back after someone deletes or a ransomware strain encrypts it. Look for two drive bays' worth of redundancy options and a quiet, business-warranty chassis. And look for a clear, supported way to copy data off the NAS to a second location, because a NAS on its own is storage, not a backup.
The trap everyone falls into: a NAS is not a backup
This is the single most expensive misunderstanding in small-business storage, so it gets its own section. A NAS keeps your data in one place. If that place is stolen, flooded, hit by a power surge or encrypted by ransomware, everything on it can go at once - resilient drives or not.
Disk redundancy protects you from a drive dying. It does nothing against fire, theft, accidental deletion or a malware attack that reaches the share. We spell this out in why RAID is not a backup. The fix is to treat the NAS as one copy in a wider plan: follow the 3-2-1 backup rule and keep at least one copy offsite and, ideally, an immutable copy that ransomware cannot alter. A NAS is a brilliant first copy and a poor only copy.
Drives, network and the bits people skip
Two practical details quietly decide whether you are happy a year in. The first is the disks. Do not put cheap desktop drives in a business NAS; use drives rated for always-on NAS duty, and for camera recording use the surveillance-rated versions, which are built for constant writing. The relative merits of spinning disks versus flash are covered in SSD vs HDD for business - for bulk NAS storage, large hard drives still win on cost per terabyte, with a small flash cache for speed if needed.
The second is the network. A NAS is only as fast as the link to it, so a single tired old switch port can throttle an otherwise capable box when several people hammer it at once. For heavier use, faster networking pays off. If your storage needs have outgrown a simple NAS - many simultaneous users, virtual machines, or strict performance demands - that is the point to look at a proper file server, which we spec out in file server and NAS sizing for 2026.