|NAS management on the move|
The key to making network-attached storage (NAS) a major component in enterprise storage is storage management. "When SRM [storage resource management] products start reporting on NAS, IT will finally be able to control it," says Randy Kerns, senior partner at the Evaluator Group, Greenwood Village, CO. Although a few NAS vendors, such as Network Appliance Inc. (NetApp), have long provided storage resource management capabilities for its own products--and even exposed their APIs for use by others--multivendor NAS management has not been practical.
But NAS management is quickly changing. "The current version of SMI-S specifies information for NAS reporting," says Kerns. Most vendors have some form of SMI-S NAS reporting or will have it soon, he adds. Once NAS can be managed alongside SAN using the same tools, it will quickly assume a larger position in the enterprise storage environment.
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."
Consolidation lowers costs by enabling centralized management. Chicago's Field Museum is typical: "We had multiple small servers with about 1TB of storage. It was unmanageable. So, we consolidated seven file servers on one NAS box," says Neil Young, manager of the museum's application and enterprise services group. Even large servers get maxed out and can't expand further, "but with NAS, we can just keep expanding as needed," he adds.
Except for the low end, NAS devices can consolidate many servers. "The filers can handle a lot if they are not swamped by client requests," Foskett explains. The limiting factor isn't the number of consolidated servers, but the volume of user traffic. Other storage managers report finding 10:1 file server consolidation is reasonable. With Citrix servers, the ratio is 6:1 due to greater client traffic. Dell Computer Corp. suggests a 5:1 to 8:1 consolidation ratio.
|How NAS fits into different storage environments|
This was first published in March 2004