NAS versus SAN

With regard to storage, there seem to be a couple great debates that make their way into just about every discussion. The predominant one is the storage area network (SAN) versus network attached storage (NAS) dispute. Depending on whom you ask, you will hear various reasons why one trumps the other and why there is a distinct difference between the two. Then again, there are proponents who do not seem to care or notice any significant difference.

SAN and NAS have remained the two key players in the ongoing struggle for IT operators to handle the ever-increasing amount of data they keep collecting. A SAN is where storage devices, such as disk arrays and tape libraries, are attached directly to the servers. One SAN drawback occurs when the server or servers go down; it means the ability to access information also is lost. A NAS involves the storage device, such as a disk array (hard disk storage), being attached directly to the network.

A NAS is best suited for users who do not require as much data-delivery horsepower. A SAN is for those with vast amounts of data that need to be moved around in bulk. Because of today’s data- driven world, SAN has made its way to the forefront, mainly since cost has come down, and users can afford SAN even if they do not necessarily need it for the time being.

The other reason why SANs have become so popular is they support some of the newer storage technologies, such as snap mirroring and archiving, and they have the ability to use a NAS. With the increasing popularity of server virtualization and storage consolidation, those needing a future-proofed storage network would most likely choose a SAN, since it has the ability to support such technologies.

Small to mid-sized operations sometimes begin with a NAS, as it is an easier, less expensive solution to get started in data storage, and it can be scaled up to a SAN.

The other option is to incorporate both a SAN and a NAS solution. Since a SAN moves around large amounts of data and a NAS is better suited for moving around files, some organizations have found having both solutions allows them to toggle between the two, depending on the task.

Just to add to the confusion

There are various types of SANs available. Once a SAN is chosen, it’s important to find the right one for your needs. Once you opt for a SAN, you need to decide which SAN you want.

Fibre Channel SAN is not to be confused with fiber. It is a gigabit technology that has become a standard operating protocol within the storage networking arena that can be run over either copper cable or fiber optic cable.

IP-SAN, also known as iSCSI (pronounced eye-skuzzy), takes its cue from Internet protocol (IP). This network runs over IP in a similar manner to IP telephony. ISCSI has been increasing in popularity because it can often be run over existing IP networks. But, iSCSI reverts back to Ethernet, which actually causes confusion.

Because of this cabling infrastructure equalization, the storage decision has become clouded by sales tactics. Storage is a hot topic and big revenue generator. More businesses are counting on storage to help alleviate pressures associated with the amount of data collection.

In addition, more mandates and laws are being implemented, forcing the hands of those who have staved off storage up until now. The Health Insurance Portability and Accountability Act, Sarbanes-Oxley and other requirements now make storage necessary for even small entities. What this means for contractors is increased work. It also means contractors need to be ready, willing and able to step outside of their comfort zone in order to service this growing market.

End-users have advanced well beyond simple voice and data networks and are now looking to add extra network functionality, such as storage. Contractors who are proactive in learning about this subject should be able to add to their work load by becoming involved in this specialized niche.

It all comes down to the cabling infrastructure. In the SAN-versus-NAS choice, both sides can’t be installed if there is not capable wiring in place to support whichever the end-user chooses.   EC

STONG-MICHAS, a freelance writer, lives in central Pennsylvania. She can be reached at



About the Author

Jennifer Leah Stong-Michas

Freelance Writer
Jennifer Leah Stong-Michas is a freelance writer who lives in central Pennsylvania.

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