The U.S. Army Reserve's 108th Division faced a massive consolidation challenge, moving the workload of 23 Windows servers at 23 locations to eight data centers. It might have built an elaborate storage area network (SAN) to hold its 2.9 TB of files. Instead, it opted for a set of network-attached storage (NAS) appliances running Microsoft Corp.'s latest storage operating system, Windows Storage Server 2003. "NAS seemed like the easiest way to go and it was also low cost," says William Bailey, network manager for Ciber Inc., Greenwood Village, CO, the consulting firm that consolidated the systems for the 108th Division.
A select group of storage managers like Bailey are bucking the trend toward "everything on the SAN" and are finding a place for NAS in the enterprise storage infrastructure. While NAS may ultimately be more limited than a SAN, these storage managers are leveraging its well-known ease of use in combination with increased capacity and new features to drive significant consolidation projects. And with more options to converge block and file storage, storage managers now can consolidate file storage with an eye toward a unified infrastructure later.
Stephen Foskett, practice manager for storage strategy at GlassHouse Technologies Inc., Framingham, MA, says the main payoff isn't where you might think it would be--replacing multiple smaller NAS devices with fewer large NAS devices.
"There aren't big savings from replacing six old NAS boxes with two newer, bigger ones. What you are getting is more reliable storage and greater storage density, which will reduce the footprint," he says. You also gain some licensing advantages and simplify the management, although management of NAS devices hasn't to date been a large issue.
Server consolidation, however, is a different story. Here, NAS can play a significant role in eliminating the plethora of servers that sprouted in companies in the '90s when direct-attached storage (DAS) was the main game and IT departments bought new application servers each time an existing one ran out of storage. Not only can you reduce the burden of managing an out-of-control server environment, but you can leverage the host of new features that have made their way into better NAS boxes. Those advanced features include replication clustering and SMI-S management.
Where NAS hasn't gained traction, at least not yet, "is for massive storage consolidation or to consolidate [block-level] enterprise application storage," says Foskett. Application consolidation remains the province of SANs. "A few companies I know are using NAS for database access, but they are just mounting it via NFS or Windows over CIFS [the Common Internet File System]," says Foskett. "It's a little like hammering a nail with a screwdriver. They do it because they can have many clients accessing the same data. They like the NAS interface, and performance isn't critical to them."
For more information, take a look at the complete Storage magazine article.
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Alan Radding is a freelance writer located in Boston, MA.
