iSCSI continues to gain market share and momentum. While the IP SAN technology has certainly come in for its share of hype, the sheer number of deployments commands respect, and trends like server virtualization and faster Ethernet connections could accelerate that growth.
"Continued, steady growth has been the watchword for iSCSI over the past year," says John Webster, an analyst at Illuminata.
According to Steve Duplessie, founder and senior analyst at Enterprise Strategy Group, there have been 25,000 iSCSI production implementations to date.
That may seem like a lot, but according to Brad Nisbet, IDC's storage systems program manager, iSCSI commands just a 3 percent share of the total external disk storage systems market. But with growth rates approaching triple digits, IDC expects iSCSI's market share to reach 21 percent by 2010.
LeftHand Networks, for one, a pioneer in the IP SAN market, reports more than 2,000 customers and 5,000 deployed systems running its flagship SAN/iQ product. Such numbers signify the emergence of iSCSI beyond its initial use by small IT shops who couldn't afford a Fibre Channel SAN. While it retains this audience, it has been able to scale upwards successfully into some high-end enterprise deployments.
Commerce Bank and Trust based in Topeka, Kansas, is a LeftHand customer. It runs 50 servers at its data center to serve 22 branches. Each branch uses workstations backed up by LeftHand appliance.
Steve Haas, Commerce Bank
Big Vendors Take the Lead
But LeftHand isn't the only game in town. Most vendors, even FC SAN stalwarts like EMC and NetApp, are now big in iSCSI. In fact, NetApp and EMC are #1 and #2 in the market, respectively, according to IDC.
"Some smaller players like EqualLogic are taking off, but NetApp is the major iSCSI vendor at the moment," says Webster.
Duplessie's figures show EqualLogic with several thousand customers (and acquiring more at a rate of 400 to 500 a quarter). EqualLogic's PS Series arrays can be joined together to form a 100 terabytes-plus combo.
Patagonia, a manufacturer of outdoor clothing and technical apparel based in Reno, N.V., uses the EqualLogic PS200E. It has a capacity of 5.6 TB.
"Our deployment of EqualLogic has been what was promised: short configuration times, up and running in minutes, and exceptional ease-of-use and management capabilities that help us grow our storage networks as needed," says Tammy Barrett, network engineer at Patagonia.
While iSCSI has certainly established its own market momentum, it has gained further traction from a couple of high-powered sources. iSCSI is now riding the coattails of two massive storage drivers VMware and Microsoft.
VMware, of course, is part of the EMC empire. But it has caught the imagination of the server marketplace in a big way.
"iSCSI seems to have an affinity with VMware," says Webster. "Find a solid VMware user and you're likely to find iSCSI."
VMware puts multiple virtual servers on a physical box, and makes it easy to move these virtual servers around. If you have 200 virtual machines across three physical systems, for example, you need to have all physical and virtual machines capable of accessing the same storage. iSCSI is a perfect way to enable that easily.
"iSCSI makes VMware capable of quickly moving from lab environments to production ones and they are so hot it's pulling a lot of iSCSI SANs along with it right now," says Duplessie.
Accordingly, vendors such as LeftHand are building additional functionality into their products. LeftHand's SAN/iQ storage virtualization and management software can now be combined with VMWare server virtualization software to facilitate storage consolidation and virtualization.
"The SAN/iQ and VMWare combination is the most sought-after solution by our customers today," says John Spiers, LeftHand's founder and CTO. "We believe the market is headed towards easy-to-manage, virtualized data centers with convergence around IP."
SAN/iQ's feature set includes virtualization, grid-like clustering, pay-as-you-grow, thin provisioning, local and remote replication and snapshots, all managed from a one screen.
Microsoft, too, is fueling the iSCSI fires. Duplessie points out that Windows now ships with iSCSI initiators included. The iSCSI initiator is the code in the server OS that lets it talk to an iSCSI target (array). Microsoft began giving it away as a free download in 2005. Now it's automatic in Vista and Longhorn. By now, there are an awful lot of machines out there ready for iSCSI. And those numbers are only going to get bigger.
10 Gig on the Way
These major market dynamics could be in for yet another boost once 10 Gbps Ethernet gets going. Analyst firm Dell'Oro Group recently revealed that the 10 Gigabit Ethernet Switch market recently surpassed port shipments in excess of 100 thousand in the fourth quarter of 2006, with annual revenues topping $1 billion during 2006. But the 10 Gb market continues to be haunted by high prices. Once the prices come down significantly, there could be no stopping iSCSI.
"We already have a number of customers asking for 10 Gig, and expect to be making announcements around our 10 Gig products in the coming months," says Spiers. "If you look at each Ethernet bandwidth adoption curve, the big inflection in demand comes when prices hit a certain point."
He reckons that point will be reached soon. A new standard has been ratified that introduces copper into the 10 GbE marketplace. That should help considerably with the high price point of current 10 Gb switches.
"We currently don't have any IP SAN initiatives," says Jim Burgard, University of New Orleans' Assistant Vice Chancellor for University Computing and Communications. "When 10Gb Ethernet interfaces become widely available for servers, we will revisit this option."
Here to Stay
The potential of iSCSI, then, is staggering. It has faced up to a series of barriers over the last few years, and passed them with flying colors.
"We've proven performance isn't an issue, though the perception still exists," says Duplessie. "It's hard to argue with an interface based on a ubiquitous standard (Ethernet). And with folks like VMware being able to really take advantage of simple, cheap networked block storage, the numbers are only going to accelerate."