Microsoft Tweaks Windows Storage for Exchange, SANs

by Timothy Prickett Morgan

By various industry estimates, Microsoft's Windows Storage System and its predecessors account for approximately half of the shipments of network-attached storage (NAS) arrays in the world. This is a pretty stunning accomplishment, but Microsoft wants a bigger piece of the storage pie and it is fleshing out the storage server variant of its Windows 2003 Server program so it can handle more of the kind of functions that only high-end arrays used to offer.

At the Storage Networking World show in Phoenix, Arizona, Microsoft announced a new feature pack for Windows Storage Server that will allow it to house information from one or more instances of Exchange Server 2003 on NAS boxes running Windows Storage Server 2003. NAS arrays use regular Ethernet-style LAN connections, a trimmed-down X86 server (usually a 1U, 2U, or 4U box with one or two X86 processors), SCSI or ATA disk drives, and a streamlined operating system designed just to handle file storing protocols to create a storage array that any machine on a network can use to house data. These NAS arrays are not as fast as direct-attached storage, so they may not be suitable for transaction processing systems, but they are a very efficient and cost-effective way to give a lot of servers and desktops access to shared storage.

With the Windows Powered NAS predecessor to Windows Storage Server 2003, Microsoft could cluster two servers together to create a fault-tolerant, more scalable NAS. Two-node clustering was not a limitation of NAS, but of Windows 2000 Advanced Server on which the Windows Powered NAS toolkit was based. Windows Storage Server 2003 was launched in June 2003 and started shipping in September. It provides eight-node clustering, just like Windows 2003 Enterprise Edition does. It also includes Multipath I/O, a feature of the regular Windows that allows up to 32 different ports for linking a server and its storage (up from two ports with Windows Powered NAS 2.0). Most high-end Unix boxes have such multiple paths, as does IBM's mainframes and midrange boxes. In the event that one I/O card or cable dies, data can still be routed between storage and server, which means applications keep running even though hardware has failed. The initial Windows Storage Server 2003 also included a new CIFS file server that could interface with Unix NFS file systems without such big performance penalties and can handle the older SMB protocol with a similar boost in performance. It also included volume snapshots, which allows the NAS server to create copies of heavily used data sets and allow users to access these multiple copies, this speeding up performance.

With the service pack, now big Exchange installations will be able to use these Windows Storage Server features to build more resilient email networks, and presumably do so spending less money than if they bought full-blown Windows 2003 licenses for real X86 servers. The new service pack also allows a NAS running WSS to be used as a print server. This is something that will probably appeal more to small customers, who only want to share printing, emailing, and filing on their server storage anyway.

Not all of the storage announcements Microsoft made this week were earmarked specifically for Windows Storage Server 2003. Microsoft also announced that a Fibre Channel information tool that will go out over the SAN and provide configuration and status information of devices on that SAN will be available free of charge on the Microsoft download site in May. Microsoft simply wants customers to manage SANs from within Windows rather than from another environment. Microsoft has also announced that it has consolidated the error tracing and event logging capabilities of Windows Server 2003 as they relate to storage components, and that all of the major storage vendors are adapting their device drivers to support this new mechanisms. This feature will be available with Windows Server 2003's Service Pack 1, due in the second half of 2004 if all goes well. Microsoft also said that the iSCSI support that debuted in June 2003 with Windows Storage Server is now supported in Windows Server 2003 Datacenter Edition, and that iSCSI devices can now make use of the multipathing I/O features of Windows 2003.