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What Are Storage Area Networks?

Vangie Beal
Last Updated May 24, 2021 8:01 am

This Storage Area Network (SAN) reference article introduces the basic purpose and function of a SAN and examine its role in modern network environments.

A Storage Area Network (SAN) is a high-speed sub network of shared storage devices. Many IT organizations today debate whether the advantages of implementing a storage area network (SAN) justify the associated costs. So, are you planning to move away from your current storage strategy towards a Storage Area Network (SAN)? Continue reading to learn about the storage area network and its role in modern network environments.

SAN Explained

Even the most complex technologies provide the most basic of functions. This is certainly true of Storage Area Networks (SANs). A Storage Area Network is a high-speed sub network of shared storage devices. A SAN’s architecture works in a way that makes all storage devices available to all servers on a LAN or WAN. As more storage devices are added to a SAN, they too will be accessible from any server in the larger network. A Storage Area Network can be anything from two servers on a network accessing a central pool of storage devices to several thousand servers accessing many millions of megabytes of storage.

SAN Advantages

Storage Area Networks (SANs) allow storage devices to exist on their own separate network and communicate directly with each other over very fast media. SANs address the bandwidth bottlenecks commonly associated with LAN-based server storage and the scalability limitations found with SCSI bus based implementations.

The advantages of SANs are numerous, but perhaps one of the best examples is that of the serverless backup. This system allows a disk storage device to copy data directly to a backup device across the high-speed links of the SAN without any intervention from a server. Data is kept on the SAN, which means the transfer does not pollute the LAN, and the server processing resources are still available to client systems. These advantages have led to an increase in the popularity of SANs as they are better suited to address the data storage needs of data-intensive networks.

SAN Implementation

Storage Area Networks (SANs) are most commonly implemented using a technology called Fibre channel. Fibre Channel is a set of communication standards that supports very fast data rates. Devices on the Storage Area Network are normally connected together through a special kind of switch, called a Fibre Channel switch that acts as a connectivity point for the devices. This provides a dedicated path between the devices in the SAN fabric so that they can use of the entire bandwidth for the duration of the communication.

Do I Need a SAN?

So, the question that remains is this: Should you be moving away from your current storage strategy and towards a Storage Area Network (SAN)? The answer is not a simple one. If you have the need to centralize or streamline your data storage then a SAN may be right for you. The price tag of SAN equipment may still be outside the reach of small businesses. If this is the case your business may need to investigate other types of storage networking technologies such as Direct Attached Storage (DAS) or Network Attached Storage (NAS).

When assessing your likely storage requirements consider how much data you have now and how much new data you are likely to create every month. Before investing in a server you need to consider many things, including the applications you will run, storage, processor, form factor, and more.

Congratulations! You now understand what advantages a storage area network (SAN) and storage networking technologies can do for your business network.

This article was originally published on March 31, 2011