Microsoft touts 'SAN friendliness'

By Lisa Coleman

A major highlight of the storage features that will debut next year with Microsoft's .NET Server will be its storage area network (SAN) support, including flexible volume mounting, boot-from-SAN, 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, many problems were created 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 logical unit number (LUN) visibility to an individual server. It also works with switch zoning.

Microsoft will also offer the capability 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 redesigned 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.

Earlier this year, Microsoft began providing its partners with a driver development kit (DDK) and APIs for automated disk and storage management services that could be built into their software applications and subsystems. Microsoft's Multipath I/O (MPIO) DDK will allow vendors to build interoperable multi-path systems via standard I/O protocol communication between third-party storage products and Windows 2000 and .NET Server 2003. Its volume shadow-copy service (VSS) and virtual disk service (VDS) provide data protection/recovery and a service layer for applications to manage heterogeneous storage arrays, respectively. Both VSS and VDS will be available for .NET Server.

Windows grabs NAS share
Microsoft's focus on storage comes in part as a result of its success in the network-attached storage (NAS) market. Windows-based NAS products have captured nearly 32% of the market, according to market research firm International Data Corp.

OEMs such as Dell, Hewlett-Packard, IBM, Iomega, and NEC use Microsoft's server appliance kit (SAK) to build Windows-based NAS appliances. Microsoft plans to introduce SAK version 3.0 approximately 90 days after Windows .NET Server debuts in 2003.

"Microsoft's strategy is to penetrate the channel and give them the friendliest OS possible, and then give the channel the opportunity to add value so that they can differentiate themselves," says Nancy Marrone, a senior analyst with the Enterprise Storage Group.

However, while Microsoft is providing MPIO, VSS, VDS, and enhanced SAN support, it does not mean that all the OEMs will take advantage of these features, adds Marrone.

This article was originally published on November 06, 2002