Open standards driving SANs to masses

Storage area networks might still be in early adopter territory but the bulk of the user population is not far behind, says IBM storage specialist Scott Drummond.

California-based Drummond, who conducted a storage roadshow in the country last week, divides SAN users into five categories. According to Drummond, they are bleeding edge users (who buy technology for technology's sake), leading edge buyers (deploying SANs now), the main body (still reading the literature, looking at the maturity of the industry and getting into bids), the cost savers (waiting until all ROI analysis is published) and the dormant (will never do anything).

Adoption of standards and the promise of interoperability among storage vendors are making SANs more attractive to the masses.

Working along both those lines, IBM and other storage vendors are busy on a new storage networking system, generally known as pooled storage. IBM's take on it is called Storage Tank which, when fully developed, will create a universal file system allowing administrators to create a virtual pool of data which can be accessed from any platform. Ultimately such a universal file system will eliminate the need for data to flow from the file server to the database server, to the application server and the web server and finally to the web browser.

With storage virtualisation, servers "think" they see physical storage when in fact they are attached to virtual storage drawn from a common pool of data. Software allows network managers to aggregate data that might be under-utilised on one server and assign it to other servers.

Drummond says storage utilisation on a LAN is typically about 50% but with pooled storage the figure jumps to 80%. However, until the software is available (and all vendors are promising to start shipping products within the next six months), true interoperability is still a way off. Until then, those contemplating a SAN should look at the software component first, because it's still the hardest part to change.

"The five key components of a SAN are servers, the SAN fabric [switches], storage media, software and services. Most people do their analysis and look at the storage control unit first. Then they look at the SAN fabric [switching] and then the software. It should be the opposite. They should look hardest at the software, then the switch, then the storage because software is the most difficult part to change.

"I'm talking about things like network management software, backup management. Once you choose those things it's hard to switch them out."

The two major switch vendors, Brocade and McData, have agreed on a standard code that will allow their products to communicate in SANs. Like a router on the internet, a switch directs data traffic over a SAN, but Drummond says despite the announcement, SAN switching is still a long way from real interoperability. Meanwhile, the actual storage hardware is the most flexible part, he says.