A Network Attached Storage (NAS) is a type of storage system that can be attached to a data network. A NAS is useful for storage related to non mission-critical data. It is cheaper and easier to maintain than a Storage Area Network (SAN) but does not quite deliver the performance an enterprise can obtain from a SAN.

File transfer protocols supported by NAS include Network File System, Common Internet File System, File Transfer Protocol, etc. NAS servers offer flexibility in terms of attachment to the network; this can be done either via the Ethernet or a fiber channel network. These days you can also get wireless 802.11 NAS devices. The beauty of NAS devices lies in their simplicity, they can be built using any disk technology though they are usually developed using Small Computer Systems Interface (SCSI). NAS devices can also be used for other storage methods such as magnetic tape, CD, and DVD.

NAS offers the following advantages –

1. Faster access to stored data via the LAN.

2. Low costs since the RAID arrays are a part of the LAN.

3. Easy to install, can be up and running in less than thirty minutes.

These properties of NAS storage plus its low cost of ownership make it ideal for SMBs. A dual advantage of NAS is that it allows administrators to either increase or consolidate the storage infrastructure. Storage expansion is virtually unlimited as one is freed from the limitation of storage capacities of individual servers and the number of disks they can hold. At the same time, one NAS set-up is good enough to replace several file servers that are operating individually, this leads to consolidation. NAS can be run on commonly available operating systems such as Windows. NAS status can be checked from anywhere on the LAN, this gives storage administrators the ability to diagnose issues and change NAS configurations when required.

NAS system performance depends on the drive support, the number of drives in use and the overall capacity. SATA drives that offer excellent low-cost bulk storage are most preferred. SCSI drives are also available. Since the NAS makes use of the LAN for data transfer there is always a chance of a bottleneck developing somewhere along the LAN, usually it is the network interface that causes problems. If implementing a NAS, look for products that support Gigabit Ethernet for quick data transfer and multiple connections so that network load is distributed and interface redundancy is provided.

When purchasing a NAS solution always keep security in mind and look for vendors that offer native encryption with the system.