Although the names sound similar, each storage technology is different. NAS stands for network attached storage, while SAN stands for storage area network.
A NAS is a unit that typically has multiple hard drives. The drives are then arranged in a RAID configuration to prevent against data loss due to hardware failure. Then, an operating is embedded in the NAS unit to preform all of the file operations, sharing, network communication, etc. Most NAS units are connected to your network via IP and can be managed through a web interface. The embedded operating system allows the unit to create users, shares, permissions, and sometimes even act as an FTP (file transfer protocol) server to allow the access of files via the internet.
NAS units offer better sharing capabilities between different operating systems such as Windows and MAC due to the different file access methods in the embedded NAS operating system. NAS units also offer many additional features, such as automated backup, bit torrent downloading, file quotas, and print sharing. NAS units are typically geared toward home networks as well as small businesses and are usually priced accordingly.
SAN units are also comprised of multiple disks configured in RAID to protect against data loss due to hardware failure. SAN units typically use higher end hard disks that spin between 10,000 RPM and 15,000 RPM for increased performance. SAN units do not have any type of embedded operating system, SANs deal with data on the block level. This means that in order to utilize a SAN in your environment, it has to be attached to a host or multiple host machines. SANs connect to their host machine via a SCSI Fibre Channel. The host machine controls the file operations, sharing, permissions, etc. Typically, SANs are used in enterprise environments, or in environments where fast I/O operations are required.
SAN units usually offer larger storage capacities due to the amount of physical hard drives they support. Also, data read and write speeds are faster in part due to the SCSI Fibre Channel link between the host server and the unit as well as the high end hard drive speeds.
NAS or SAN for your business?
Choosing the right storage unit can be tricky. A NAS is a good choice if your organization is looking to create a centralized file storage system or your organization just needs some extra file storage. If you are a larger enterprise and larger storage requirements as well as read write performance are necessary, then it may be wise to invest in a SAN over a NAS. Although it may sound trivial, you should consider all of the factors when choosing your attached storage platform. Your organization can either spend a great deal of money more than it needed to, or your applications can be robbed of performance.