THE NUMBER and variety of iSCSI SAN options is growing by leaps and bounds. The past couple of months have seen significant iSCSI announcements from Hewlett-Packard, Brocade and, most notably, Microsoft. Furthermore, server virtualization superstar VMware stands to jolt the market for iSCSI arrays this summer, when the iSCSI-friendly ESX Server 3 comes out of beta.

Hewlett-Packard's latest foray into the iSCSI market comes via its midrange modular EVA SAN arrays, which can now be outfitted with an iSCSI Connectivity Option. With it, EVA users can gain concurrent access to the array via either Fibre Channel (FC) or iSCSI, or can use the entire EVA exclusively as an iSCSI target. The option is available for new and existing EVA arrays.

Brocade's iSCSI offering is called the Brocade iSCSI Gateway, or BIG, which consists of two Gigabit Ethernet ports and two FC ports. Based on technology from Sanrad, BIG could theoretically be used to connect up to 100 hosts to an existing SAN array.

Of interest to smaller shops, Microsoft will begin offering an iSCSI target as part of its Windows Storage Server (WSS) 2003 R2 release this summer. Thus far, Microsoft has limited its iSCSI wares to a software initiator--the driver that allows a host to connect to an iSCSI array. The addition of iSCSI target software promises an end-to-end, all-Microsoft block storage environment.

Microsoft's iSCSI target code comes by way of its acquisition of the technology assets of String Bean Software. The product, WinTarget, was developed exclusively for Windows, and includes Virtual Disk Services (VDS) and Volume Shadow Copy Service (VSS) support.

The iSCSI target option won't be available to end users, only to WSS R2 licensees, including big names like Dell, Hewlett-Packard and IBM. "The only ones you won't see are EMC and Network Appliance," says Claude Lorensen, Microsoft's group product manager for storage. He expects most WSS licensees to adopt the iSCSI target add-on.

Does Microsoft's entrance into the iSCSI marketplace mean impending doom for the handful of iSCSI array vendors that have carved out a market for themselves? John Joseph, VP of marketing at EqualLogic, doesn't think so. When he looks at WinTarget, he says, "I don't see the layers of intelligence that EqualLogic brings to the table," like automated load balancing, space-efficient snapshots and clustering support. In his mind, Microsoft's WinTarget will be applicable for shops with a maximum of 10 servers and no pressing scalability needs.

Indeed, some iSCSI shops, like Poe Financial Group, an insurance company in Tampa, FL, are pushing the envelope of how far modern IT will go. Using a combination of VMware server virtualization, NSI Software's Double-Take replication and an iSCSI SAN from LeftHand Networks, Eric Tuley, Poe's senior systems engineer, boasts that from the time of a declared disaster, he can get his environment up and running in about an hour. "I challenge any bigger shops to be able to say that," he says.

With his eye on using VMware's VMotion to perform maintenance on virtual machines, Tuley is beta testing ESX Server 3, which comes with a native iSCSI initiator as part of the kernel. With previous versions of ESX Server, if you wanted to use iSCSI, you had to install initiators within the virtual machine, "and it just wasn't stable," says Tuley. So far, the iSCSI component has been working flawlessly, he reports.

"Actually, we're seeing 90% of the performance of ESX Server to our FC SAN; that surprised us," he says.

--Alex Barrett