NAS and SAN: The Differences

NAS Storage array

NAS (Network Attached Storage) and SAN (Storage Area Network) are two different types of solutions that companies can use to make stored data available to multiple users at once. While these solutions both provide a similar service, they do so in different ways. Before comparing them, let’s define what they actually do.

NAS

NAS is a piece of hardware with multiple hard drives, acting in RAID to protect the data. It is attached to the network either with a network cable or a wireless setup. The NAS allows access to data from a central location to as many users and groups of clients as necessary. For small to medium sized organizations, NAS has many benefits. It’s incredibly cost-effective, especially when compared to SAN, and is easy to set-up and deploy. However, one downside is that it creates a single point of failure. For instance, if the power supply goes then the entire system will fail. It also doesn’t scale as well as a SAN.

SAN

SAN is a more advanced version of a NAS. It is not a storage machine, it’s a storage system that provides high performance, low latency access to data. It does this by having multiple servers (using fiber optics) connected to multiple switches that connect to a set of arrays. These arrays can be easily expanded and scaled over time. SAN runs on its own network which prevents bottlenecked speeds. It also protects the data from single points of failure: if a server were to go down there are other devices to pick up the slack.

The benefits of using SAN are obvious, but the downsides to it are as well. A SAN solution is expensive, not only in building it, but also in maintaining it. Most SAN setups require an IT professional to configure it. As this is the case, SAN is usually reserved for organizations or companies that are large enough to be able to shoulder the cost.

Which One?

At the end of the day, the best data access and storage solution is going to be a tradeoff. NAS will come up short in speed and fail states but provides excellent access to storage that is easily set up and managed at a cost-effective price point. SAN provides greater protection, providing redundancy and better speeds at a much higher price point.