Apr 11, 2011

What is network attached storage?

What is network attached storage, and what devices does it cover?

Hi Spencer,

Here's a good background article that will give you an overview of Network Attached Storage.


"Network-attached storage (NAS) is file-level computer data storage connected to a computer network providing data access to heterogeneous clients. NAS not only operates as a file server, but is specialized for this task either by its hardware, software, or configuration of those elements. NAS is often made as a computer appliance – a specialized computer built from the ground up for storing and serving files – rather than simply a general purpose computer being used for the role.[nb 1]

As of 2010 NAS devices are gaining popularity, as a convenient method of sharing files among multiple computers.[1] Potential benefits of network-attached storage, compared to file servers, include faster data access, easier administration, and simple configuration.[2]

NAS systems are networked appliances which contain one or more hard drives, often arranged into logical, redundant storage containers or RAID arrays. Network-attached storage removes the responsibility of file serving from other servers on the network. They typically provide access to files using network file sharing protocols such as NFS, SMB/CIFS, or AFP."

Beyond the traditional “hardware” NAS device, there is also a “virtual” NAS option for managing local storage and backup. 

A virtual NAS is a lightweight, downloadable software appliance that operates within a virtualized environment such as Xen or VMWare. Typically, a virtual NAS is backed by a cloud service provider such as Amazon S3 or Windows Azure. It is through this connection to the cloud that a virtual NAS gains additional functionality such as automatic offsite file protection, disaster recovery and an unlimited storage capacity.


For IT managers at small and medium-sized enterprises looking to expand their storage infrastructure and simplify their data management process, a cloud-based virtual NAS is an excellent alternative to a traditional NAS device.


NAS stands for network attached storage (NAS), a fairly generic term that describes a hardware appliance running special software that provides shared storage for users across a network.


The basic components of a NAS unit are a box (that doesn't look like a PC) with a power supply (or two), equivalent electronics to a PC to run the operating system, and from one to 32 (or more) hard drives. They have no keyboards or monitors attached.

Very small to very large. Some vendors use the same housing and disk drive for a NAS as they do an external USB hard drive, but with a network rather than a USB port. These are inexpensive and great for small groups of local users.


Desktop NAS units have become quite popular over the last decade for small companies and workgroups. These tend to have two or four disks for data redundancy (RAID 1 needs two disks to mirror data on both disks, while RAID 5 stripes data across four disks). These units are quieter than a PC and are small enough to almost disappear in a modern office.


Large NAS appliances are rack mounted units that hold large numbers of hard drives. The housings look exactly like enterprise servers and disk systems, and the differences between a NAS and a server or a Storage Area Network are internal. A NAS provides file-based data storage services to other network devices, such as client computers and servers.

Answer this