Microsoft touts 'SAN friendliness'

iSCSI support due next year

By Lisa Coleman

A major highlight of the storage features that will debut next year with Microsoft Windows .NET Server will be its storage area network (SAN) support, including flexible volume mounting, "boot-from-SAN" capability, optimized drivers for Fibre Channel, and enhanced host bus adapter (HBA) management.

Previously, Windows was not SAN friendly, according to analysts. If it was installed in a SAN, problems often cropped up because the operating system assumed that all the SAN volumes belonged to it. To solve these problems, Microsoft is adding flexible volume mounting, which allows for control of the logical unit number (LUN) visibility to an individual server. It also works with switch zoning.

Microsoft will also offer the ability to "boot-from-SAN," which requires support from hardware vendors. Previously, Windows required booting from a disk attached directly to the main server, which could cause problems if the server with the boot LUN crashed. Now, users can run diskless servers since the operating system is on the SAN, and the page file can also "live" on the SAN or can reside locally if users decide not to make servers entirely diskless.

The company has also re-designed its Storport driver for Fibre Channel SAN and HBA RAID. The driver will supplement the SCSIport driver, which in turn, has been optimized for direct-attached storage. Storport will provide an expansion path for future interconnect standards, including iSCSI. In addition, Microsoft will support the Storage Networking Industry Association (SNIA) HBA API.

Microsoft will support iSCSI after the specification is finalized, according to Zane Adam, director of product management and marketing in Microsoft's enterprise storage division. However, iSCSI support will not be built into the first release of .NET Server 2003. Therefore, users will have to use Microsoft's iSCSI initiator to take advantage of the interconnect.

Microsoft's iSCSI initiator leverages the existing network stack, and iSCSI HBAs are supported via SCSIport or Storport. Windows management instrumentation provides management across all iSCSI drivers. The initiator uses a discovery architecture for secure target management and leverages iSNS, static addressing, and vendor-supplied information. In addition, IPsec support is provided for the software initiator and HBAs. (For more information about iSCSI, see the Special Report in this issue, p. 30.)

This article was originally published on December 01, 2002