Network Attached Storage (“NAS”) is mass storage directly connected to a computer that is connected to a network and that serves the mass storage, as file-based storage, to other computers on the network.
A file server is a NAS device, however, a typical file server will also serve many other facilities to the network. Purpose-built NAS devices are available with much thinner operating systems, making them less expensive and arguably more reliable than fully-featured operating systems (there’s less things to configure and less things that can go wrong).
NAS uses file-based protocols to make available the mass storage to the network.
Network file servers were initially conceived as devices that would decrease the cost of storage while also facilitating collaborative working, by allowing network clients to share access to files. Over many years, much greater intelligence has been implemented in to network operating systems. NAS devices, being far less intelligent than their network file server counterparts, are a new approach to deliver low cost storage.
Whereas NAS devices can support many terabytes of data capacity, they have two main draw-backs:
- when serving high capacities of data they perform less well than a SAN
- if/when storage capacity needs to be increased, the upgrade can be disruptive to normal computer network operations