First NAS
A first NAS enclosure, chosen on bays before terabytes
The enclosure is a five-year decision and the drives inside it are not, which is why bay count deserves more thought than capacity. The second decision is the software, because that is what you will actually use every week — and the third is being clear about what redundancy in this box is for.
By Jean-Benoit Buisson
Choose the bay count first, because it is the part you cannot change
Capacity is revisitable at any moment by buying a bigger drive. Bay count is not: adding a bay means a new enclosure and a migration, and migrations are the job nobody volunteers for.
One bay is a place to put files, and every question about protection lives outside the box entirely.
Two bays can hold two independent volumes or one mirrored volume, which gives the capacity of one drive and keeps the volume readable when the other fails.
Four bays and up is where distributed redundancy starts to make sense, because giving up one drive’s worth of capacity costs proportionally less the more drives there are. It is also where the unit becomes audible.
Where the enclosure allows it, buy it empty and fill it over time. A spare bay is an upgrade path; a unit full on arrival is a migration with a date on it.
Be exact about what the redundancy is for
This is the point on which the site does not equivocate.
A redundancy level buys continuity: the volume survives the failure of a drive, and you replace that drive without stopping. That is worth having and it is what the feature was designed to deliver.
It does nothing about the events that reach every drive at once — a file deleted, a folder overwritten by an application or a synchronisation running the wrong way, software encrypting what your account can reach, a power event, a theft, a fire. Nor does it help if the enclosure itself fails in a way that makes the array unreadable outside that machine.
So the enclosure and the copies are two purchases, not one. What the enclosure can contribute to the second is snapshots or file versioning, which keep previous states of a file and are the feature that recovers something overwritten. Check whether the enclosure offers them, how far back they reach and how much space they need.
The software is what you will live in
Two enclosures with identical hardware are different products if their software differs, and for a first NAS the software is the larger part of the experience.
Look at how shares and users are created, because a household with several people needs more than one account and a sensible way to decide who sees what. Look at the mobile and desktop applications, particularly whether photographs from phones can be brought in automatically, since that is the job that turns an enclosure from a novelty into infrastructure.
Look at snapshots, at what the maker publishes about update policy, and at whether the unit can copy itself to somewhere else on a schedule — an external drive, another enclosure, a remote service — because that is the mechanism your copy routine will use.
And look at what happens if the enclosure dies: whether the drives can be read in another unit of the same family, and what the maker documents about that.
Ports, processors and the ceiling on a transfer
The network port is the ceiling for everything the enclosure serves. A gigabit port is the common case and serves a household comfortably; a faster port matters when a specific machine at the other end can also use it, and when the drives inside can sustain it.
The processor and memory decide what the unit can do beyond serving files: several people at once, media handled on the fly, containers or applications. A first NAS used as shared storage asks very little of them; a first NAS that becomes a household’s media system asks a great deal.
Expansion is worth a glance — a socket for a solid-state card to hold the small, busy part of the workload, or an external port for a copy target.
Noise and heat decide where it can stand
A multi-bay enclosure with mechanical drives makes noise: a fan, and the drives themselves seeking. In a cupboard or a utility room this is irrelevant. In a bedroom or a study it is the specification you will regret ignoring.
Read what the maker publishes about the fan, and about the clearance the unit needs around it. Then choose a position that satisfies the clearance rather than one that satisfies the furniture.
Capacity, last, and in the maker’s units
Once the bays are decided, the drive size is the easy part. Buy for the collection plus growth, leave real headroom rather than planning to run drives near full, and remember that a machine displaying in units of 1024 will show a different figure from the one printed on the drive. Both describe the same hardware; compare drives in a single unit and plan against the maker’s own number.