UK What NAS is
NAS, or network attached storage, is storage that sits on the network rather than inside a computer, and shares its capacity as files and folders. Any authorised computer on the network can open, save and share those files at the same time, as if they were on a local drive.
A NAS device, sometimes called a NAS server or NAS box, is a small dedicated computer built for that one job. It has a processor, memory, an operating system tuned for file serving, one or more network ports and a set of drive bays. The term “NAS drive” is used both for the whole device and for the hard drives designed to go inside one.
How a NAS works
A NAS stores data at file level. The computers that use it ask for a file by name and path, and the NAS’s own file system decides where the blocks live on its drives. Windows clients usually connect with SMB, Linux and Unix clients with NFS, and many devices also offer FTP, rsync and cloud sync.
-
//
Drive bays and RAID. Two to a dozen or more drives are combined into a RAID array, so the NAS keeps running when a drive fails and the failed drive can be swapped.
-
//
Network ports. Gigabit Ethernet is the minimum. 2.5GbE and 10GbE networking let several users or cameras read and write at once without the network becoming the bottleneck.
-
//
Users and permissions. Shares, user accounts and access rights are set in the NAS, often linked to an existing directory such as Active Directory or LDAP.
-
//
Snapshots and replication. Point-in-time snapshots recover deleted or encrypted files, and replication copies data to a second NAS or the cloud.
-
//
Management. Set-up and monitoring run through a web interface, with drive health alerts by email or SNMP.
NAS vs DAS vs SAN
NAS is one of three ways to attach storage, and the difference is how the storage is reached and at what level. Direct attached storage is connected to one computer. A SAN, or storage area network, shares raw blocks over a dedicated network, so each server sees what looks like a local disk.
| Type | Connection | Access level | Shared between hosts | Typical use |
|---|---|---|---|---|
| NAS | Ethernet (TCP/IP) | File | Yes, many clients at once | File shares, backup targets, video and media libraries |
| DAS | SATA, SAS, NVMe, USB, Thunderbolt | Block | No, one host | Local drives, drive bays and external enclosures |
| SAN | Fibre Channel, iSCSI or NVMe over Fabrics | Block | Yes, through LUN assignment | Databases and virtual machine storage |
The lines blur in practice. Many NAS devices can also present part of their capacity as an iSCSI target, so one box serves files to desktops and block storage to a virtual machine host.
What a NAS is used for
A NAS earns its place wherever several people or systems need the same data, or wherever data needs a second home away from the computer that made it.
-
//
Shared files. Project folders, drawings and documents that a team works on together.
-
//
Backup target. A central destination for scheduled backups of PCs and servers, ideally copied again off site.
-
//
Video and camera recording. Network cameras or a recorder writing footage to a NAS for longer retention.
-
//
Machine and process data. Logs, historian exports, test results and images from inspection stations, gathered in one place for analysis.
-
//
Edge AI data sets. Training images, model files and results shared between several edge computers on site.
NAS at the edge and on industrial sites
Desktop NAS devices are designed for an office: a cooling fan, a typical operating range of around 0 to 40 °C and an external power brick. On a factory floor, in a substation or at a remote site, storage often has to share a cabinet with control gear, survive dust and heat, and run without a technician nearby.
That is why industrial file storage is often built on a rack-mount or wall-mount server rather than a consumer NAS. Many of our rack mount servers support RAID across their drive bays, several add 10GbE SFP+ ports, and any of them can run a standard file-server operating system with SMB and NFS shares. Pair the server with one of our managed industrial Ethernet switches and keep the storage on its own VLAN, so file traffic does not compete with control traffic.
Size the storage on write rate and retention, not just capacity. A single camera stream at 4 Mb/s writes around 43 GB a day, so 16 such cameras fill roughly 21 TB a month before RAID overhead. Choose drives rated for that continuous workload, and leave headroom for a rebuild after a drive failure.
Quick answers on NAS
NAS: common questions
What does NAS stand for?
Network attached storage. Storage that connects to a network and shares files with the computers on it, rather than being fitted inside one computer.
What is a NAS server?
A computer dedicated to sharing storage. It runs a file-serving operating system, manages its drives as a RAID array and shares folders over SMB or NFS. Any server can do the job; a NAS is one built for it.
What is a NAS drive?
Either the device or the drives inside it. Hard drive makers sell “NAS drives” rated for 24/7 running and multi-drive vibration. The term is also used loosely for the whole NAS device.
Is a NAS a backup?
Not on its own. A NAS with RAID survives a drive failure, but deletion, ransomware, fire or theft can still take the data. Use snapshots and copy it to a second location.
Can a NAS use SSDs?
Yes. Many NAS devices take SATA or M.2 NVMe SSDs, as a cache in front of hard drives or as an all-flash array for faster access.
We build networked storage into edge and industrial systems as standard, specifying the server, drives, RAID level and network to the data rate and retention you need, then validate the system before it ships.