You’ve heard the question: What’s better, NAS or SAN? Few people understand that like apples and oranges, NAS and SAN cannot be compared because the purposes they serve are completely different.

A NAS Overview

Infinite descriptions for NAS (network attached storage) exist, but NAS is essentially a computer with attached storage and an operating system that is streamlined to perform only the simple task of transferring files. Speed is compromised because the NAS is completely reliant on its network interface. If speed is not an issue and file transfer capabilities are all you’re looking for, NAS may be the best solution. Another limiting factor for NAS is problems in less common protocols such as Appletalk.

SANs in Brief

On the other hand, businesses that require massive file transfers at high speed should utilize a SAN (storage area network). A SAN enables the transfer of data between computer systems and storage devices along a communication infrastructure, including the physical connections and a software management layer.

The SAN acts as a secondary network to the LAN. Each server and storage device on the SAN uses SCSI or fibre channel protocol to connect to the SAN switches or hubs, resulting in each server receiving high-speed access to the data storage. Because each network server is able to access all information on a file serving SAN like a directly connected disk (the same protocol servers use to communicate with their direct attached disks), the file transfers occur at the same speed on a SAN as they would on a server.

What does it all mean?

In the last few years, NAS companies have claimed to be a sort of “storage miracle” that provides the fastest and best technology at a very inexpensive cost. Rather than a device that instantly allows users to network to storage, a NAS is merely a server with an operating system and several drives attached.

In most cases, manufacturers typically build a NAS using disk drives (usually IDE) and a low-end CPU – essentially the smallest server on the market today. NAS appliances offer reliability at a low price, but can send and receive data only via the LAN protocol, limiting performance.

On the other hand, SANs provide direct disk access and are infinitely scalable and flexible. For example, 10TB can be added to a SAN and disk space can be designated to the server that needs the extra space. The typical SAN user can manage about four times more storage in a SAN when compared to direct-attached storage.

To SAN or Not to SAN?

Basically the SAN versus NAS debate boils down to your company’s file transfer requirements. If you require reliability and open-ended systems, only a SAN can meet your needs.