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NAS puts data within easy reach

There are differences between NAS and SAN

By J.B. Miles, Special to GCN

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NAS appliances are easy to set up, making them ideal for remote sites

The lowdown

What is it? A NAS appliance is a single-purpose thin-client server with a stripped-down, embedded operating system and an architecture that is attached to the network. Its main purpose is to serve up files to multiple clients using various operating systems. It does this efficiently because of its fast I/O processing cycles.

When do you need one? You need a NAS appliance when your general-purpose servers cannot efficiently manage the heavy network load of hundreds or thousands of daily file exchanges.

When don’t you need one? You don’t need NAS for occasional file sharing, or when your general-purpose server is sufficient for handling multiple file transfers without bogging down the network.

Must know info? NAS appliances are highly scalable—many range from hundreds of gigabytes to multiple terabytes of capacity—with hot-swappable components and fast I/O processing. For file serving, they deliver better performance at less cost than a general-purpose server.

In this report

NAS puts data within easy reach

There are differences between NAS and SAN

NAS and SAN are two different technologies, but many people confuse them.

Network-attached storage devices connect directly to the network and sit between application servers and file systems. They incorporate industry-standard network file system interfaces such as Structured File Service and Common Internet File System over TCP/IP to let clients using different operating systems share files. They use block-level interfaces to communicate with storage subsystems and file-level interfaces to connect to the outside.

A storage area network isn’t a network device but a dedicated storage network used to connect storage systems, backup devices and servers. A SAN might be in a single box, or span multiple systems. A Fibre Channel switched network is, in effect, a SAN.

Many people persist in representing NAS and SAN as competing technologies, but they are complementary in that they work equally well for different purposes.