iSCSI Races Up The Storage Chain

Skeptics of IP storage will be disheartened to learn that the buzz about iSCSI-based SANs is getting louder. While iSCSI, the long-touted protocol for interconnecting hosts and arrays over TCP/IP networks, has been a standard for about a year-and-a-half, it is now on a tear. Although some issues still need to be resolved, it's already becoming a disruptive force.

The numbers speak for themselves. Last year, $106 million was spent worldwide on iSCSI-based disk systems, according to IDC (see "Poised For Growth," right). While that's miniscule, it's nearly a sixfold increase over the previous year. This year, IDC forecasts sales of iSCSI-based systems will nearly triple to $307 million, while jumping to $700 million next year and $1.5 billion in 2007.

Worth noting is that systems in the $15,000-to-$50,000 range comprise the largest number of iSCSI storage systems, followed by the $10,000-to-$15,000 area, both of which are key to storage integrators.

"Yes, iSCSI is a small market, but it's growing like gangbusters," says David Hitz, a founder of Network Appliance, which was an early adopter of iSCSI.

The volume of the iSCSI buzz got notably louder in February when EMC threw its weight into the game (with that of partner Dell) by adding native iSCSI support to its Clariion lines--specifically with the releases of the new AX100i and CX500i and the planned release of the CX300i this quarter.

Since the launch, Dell has heavily promoted its new iSCSI line.

"Dell generally doesn't place a bet on a market like this until they feel they can not only move the market, but dominate the market," says Jay Krone, EMC's director of platform marketing.

Matthew Brisse, technology strategist for the office of the CTO at Dell, says that IP has a successful history of usurping protocols, such as ATM and Token Ring, making a bet on iSCSI a no-brainer. "If you look through history, every protocol that has gone up against TCP is no longer in existence," Brisse says.

Not that everyone is betting on the demise of the current, dominant SAN interconnectivity protocol--Fibre Channel--anytime soon. For one, iSCSI only supports 1 GBps, while Fibre supports10 GBps. That will change when a version of the iSCSI spec that supports 10 GBps becomes a standard.

"Ten-gig levels the playing field," says Steve Paulhus, strategic marketing manager, CTO office, at Adaptec.

But 10 GBps will require devices called TCP Offload Adapters, which will prevent the interconnection from utilizing CPU cycles. If that adds to the cost of iSCSI in any major way, that could be a barrier, some observers warn.

Other new functions will give iSCSI more viability, such as Microsoft's new iSCSI Initiator 2.0, which adds support for Multipath IO and is intended to improve performance by supporting load-balancing and failover when connected to any Windows 2000/2003 Server platform. It also will support the new x64.

Another key feature will be the iSCSI Management API (IMA) from the Storage Networking Industry Association (SNIA).

"We think it will speed to market the ability of iSCSI devices to be accepted and to be managed," says Ray Dunn, industry standards marketing manager at Sun Microsystems and a member of the SNIA board.

But John Matze, CTO of Overland Storage, says not to count on vendors such as Veritas to throw away their proprietary management APIs in favor of IMA overnight. "In my view, there's a vested interest for some of these vendors not to promote this as fast as the industry would like," he says.

But if IDC's forecast stays on track, and customers ultimately insist on support for it, vendors will have no choice.