What is network-attached storage (NAS)?

Network-attached storage (NAS) is a dedicated device providing shared storage services to network users.

NAS is a type of dedicated file storage device that provides local-area network (LAN) nodes with file-based shared storage through a standard Ethernet connection. It operates as an independent network node on the LAN and is comprised of one or more hard drives arranged into logical, redundant storage containers or RAID (Redundant Array of Independent Disks).

NAS devices, which can be a hardware appliance or a software application, serve files over a network. They are connected to a network and assigned an IP address, allowing both application programs and users to store and retrieve data. This is in contrast to direct-attached storage (DAS), which is attached directly to a computer and is not networked.

NAS devices are flexible and scale-out, meaning that as you need additional storage, you can add on to what you have. A network-attached storage device is more like a file server with both storage and a file system. This is often contrasted with SAN (storage area network) and DAS (direct-attached storage), which are more like disk drives that can be accessed over a network rather than true file servers.

NAS uses file-based protocols such as NFS (popular on UNIX systems), SMB/CIFS (Server Message Block/Common Internet File System) (used with MS Windows systems), AFP (used with Apple Macintosh computers), or NCP (used with OES and Novell NetWare). NAS units rarely limit clients to a single protocol.

The key benefit of NAS is its ability to provide multiple clients on the network with access to the same files. This makes it very useful for enterprises with large amounts of data to store and access, as it allows employees to collaborate on projects without having to transfer files back and forth between individual computers. NAS also provides a simple way to share files among different operating systems, as it typically supports a variety of network protocols.

In summary, NAS is a dedicated device that provides shared storage services to network users. It operates as an independent network node, serving files over a network and allowing for easy file sharing and collaboration.