Last week Microsoft announced that version 2.0 of its iSCSI Software Initiator software would be in general release sometime in mid-April. The market's broad acceptance of the initial version of the Microsoft iSCSI software bodes well for the new features in version 2.0 and makes the Windows Server OSs more appealing to high-level storage users.

As expected, version 2.0 supports Windows Server 2003 x64 Edition and adds support for Microsoft Multipath I/O (MPIO) along with the inclusion of the Microsoft iSCSI device-specific module (DSM). DSM support means that Microsoft iSCSI users can take advantage of load balancing and failover on the Windows platform when using iSCSI storage devices and also will make deployment of these multipathing storage solutions easier.

The Microsoft DSM isn't the only DSM that the Microsoft MPIO architecture supports, so third-party vendors will be able to release their own DSMs to plug into MPIO. MPIO's support for multiple DSMs strengthens the iSCSI position vis-a-vis Fibre Channel storage solutions. As products appear that offer the failover and load-balancing capabilities the iSCSI software supports, high-end users will have reasons to consider the Windows Server platform to support storage solutions that wouldn't previously been feasible under Windows Server OSs.

I've written about iSCSI in this column before, most recently the mid-2004 third-party product announcements (see "iSCSI Storage In Demand"). In November 2004, Microsoft extended the Windows Hardware Quality Labs (WHQL) and Designed for Microsoft Windows hardware logo programs to include support for the existing first-generation iSCSI initiator. Microsoft has continued to push for iSCSI support from third parties and has gotten it not only from small storage vendors looking to make their mark but also from storage-industry leader Network Appliance (which considers Microsoft a competitor) and infrastructure leaders such as Cisco Systems and Broadcom.

As 10 Gigabit Ethernet makes inroads into the networking space, the practicality of iSCSI solutions versus SAN and NAS storage becomes clearer. Notwithstanding improvements being made in Fibre Channel bandwidth, responsible IT professionals should give iSCSI a serious look while considering the direction that their business storage model will take. The Microsoft iSCSI presence gives Windows users the opportunity to build large high-performance storage networks without having to add non-Microsoft OSs to their environment, thereby giving them a homogenous management task and simplifying the architecture of their large networks. The performance of current-generation networking systems combined with the new version of the Microsoft iSCSI initiator brings practical high-performance storage networking into the Microsoft fold.

Although Microsoft's storage-networking efforts are perhaps not a concern to the large corporate enterprises that have been building and using storage networks for the last few years, they'll have a major impact on the small-to-midsized business (SMB) space, where practical storage networking on a budget has been a major concern. With Microsoft pushing in this space, iSCSI-based storage networking becomes a check box item for an SMB that's implementing Microsoft networking. This solidifying of the iSCSI presence at Windows-based SMBs increases the market opportunity for storage vendors while pushing the door closed on the dedicated Fibre Channel storage-networking market. How this dynamic plays out in 2005 should be an interesting story to watch.