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Customer response to VSS has been positive. "A quick review tells me there are some very strong business cases to be made to take advantage of .NET Server's new features," says Larry Scott, manager of server support with Dollar Rent-A-Car of Tulsa, OK, which is using .NET and Web services standards to rebuild many of its core business applications. "Now we do traditional backup from servers onto tape; it's always laborious to have to retrieve tapes to do a restore. [.NET] features could be very time-saving if we implement them properly." .NET Server will also ship with a utility called volsnap.sys that creates copy-on-write shadow copies.
Snapshots aren't .NET's only enhancement to Windows storage technology. For example, improvements to the Diskpart.exe command-line tool - copies for W2K and WNS (beta) are now available at
Distributed File System (DFS) environments also get a boost. Administrators will gain more flexibility in DFS configuration, with faster server-to-server replication and a distributed server topography that provides failover after server failure. This feature also reflects .NET's distributed nature by enabling distributed storage environments and allowing clients to choose the nearest DFS server to connect to.
Businesses using storage area networks (SANs) will find some relief in Windows .NET Server. Microsoft has redesigned its driver and port model, which has so far focused on ATA and SCSI devices. The new version, called StorPort, incorporates better support for the architectural differences of SAN and NAS (network-attached storage) devices as well as emerging standards like InfiniBand and iSCSI.
Using the Mountvol.exe tool, administrators can override automatic volume mounting which controls how LUNs are visible to particular servers. Manual mounting allows storage administrators to better control SAN zoning as well. Up to 128 targets with 255 LUNs each are supported.
Will this change the behavior of Windows in mounting LUNs on a SAN?
Clusters can be extended onto SANs to allow all disks to be recognized as shared disks. Depending on hardware capabilities, administrators will also be able to boot a .NET Server environment remotely over a fiber-attached SAN. This obviates the need for locally-attached storage, supporting a greater degree of consolidation onto the single SAN.
Also helping administrators navigate SAN topography is a built-in Multipath I/O (MPIO) driver. MPIO allows definition of a number of different paths between storage and server, improving redundancy and availability in the event of connection interruption. It's long been supported in many Unix environments and through third-party Windows add-ons, but its incorporation into .NET Server - the basic driver will support up to 32 paths - provides a common redundancy architecture that will be a godsend to widely distributed SAN environments.
"Ultimately it's about bringing together the stream-based file system world with the RDBMS [a relational database management system, such as Oracle] world and presenting a very simple schema layer to applications," says Microsoft's Goodman.
This ease-of-use philosophy will be extended as customers increasingly adopt Windows-based storage appliances. Since Microsoft released its Windows-based server appliance kit (SAK) for OEMs last year, Windows-based devices have rapidly elbowed their way into a market dominated by boxes based on proprietary operating systems. Analyst firm IDC recently reported the Windows devices had seized 25% of the overall NAS market, with estimates predicting their share could grow to 60% by next year.
With Microsoft set to update the SAK twice a year, it won't be long before Windows-based storage systems become tightly integrated with the storage management capabilities of .NET Server. And while the Windows-based appliances may not offer the lightning-fast NFS performance of their highly optimized competitors - reports suggest Microsoft's CIFS tweaks have been more fruitful - their low cost and easy .NET-based management should make them a valuable adjunct to long-term storage strategies.
The customer approach
Storage management vendors are working closely with Microsoft's ESG to stay abreast of new .NET Server features to ensure their own platforms add value to Microsoft's core functionality. Expect .NET-aware upgrades of major backup apps at or shortly after the launch of .NET Server.
Despite Microsoft's history of making applications bigger with every upgrade, early signs suggest that .NET applications are actually smaller than their .ASP counterparts.
This was first published in August 2002