Many small-midsized businesses (SMBs) are faced with a tough choice today: Should they implement network-attached storage (NAS) or a storage area network (SAN)? Both SAN and NAS prices are declining, and vendors now offer more choices for smaller businesses, but the NAS/SAN decision hasn't gotten any easier. NAS is finding its way into the home offices, and the SAN is being targeted at ever-smaller businesses. The larger SAN vendors are introducing platforms for the small business, such as Dell Inc., with its recent EqualLogic Inc. acquisition, or Network Appliance Inc.'s StoreVault platform. These two product lines allow businesses to grow without regularly replacing their storage infrastructure as data storage requirements expand.
If your organization has a mix of unstructured and structured (database-type information), then go with a mixed offering. For many SMBs, an iSCSI SAN is a good option; in many cases, Fibre Channel is too expensive to implement and may be overkill. Nearly all iSCSI platforms offer two methods of access to the physical storage. The first is a traditional SAN. There are additional network cards in the servers and a separate network switch connected to the storage. The users never see or use that network segment -- the only communications being between the server and the storage itself. However, another network card in the iSCSI SAN controller connects the storage with the main user network. An administrator configures an area on the server as they normally would with a standard Windows file share and assigns the necessary permissions on it. Using the SAN to provide native file-serving capabilities takes all the file servers away, saving businesses at least $2,500 per server that would otherwise be used on hardware and maintenance of a Windows or Linux box.
NAS offerings today are a good choice for the branch-office environment with a dozen or so workers. However, if a business hosts more than one or two application servers, the commercial arguments for implementing a SAN with file sharing capabilities is a compelling one.
About the author: Mark Arnold, MCSE+M, Microsoft MVP, is Principal Consultant with LMA Consulting LLC, a Philadelphia, PA-based private messaging and storage consultancy. Mark assists customers in designs of SAN-based Exchange implementations. You can contact him at firstname.lastname@example.org.