NAS Virtualization — Selecting The Product That Fits Your Needs

NAS virtualization is a software-based solution that, in its broadest definition, lets you manage a heterogeneous environment including stand alone and clustered servers, workstations and PCs as one storage pool that can be managed, monitored and administered from any console. When one device reaches its limit, the NAS storage virtualization software automatically starts allocating storage from that device to another NAS device or file server in the same pool . Better yet, the more sophisticated systems stripe files across RAID systems connected to different servers and re-stripe them transparently when new RAID systems are added.

A NAS (Network Attached Storage) system is a single-purpose device designed to be easy to purchase, implement and use. It combines a file server with the storage array in a single, integrated appliance, also referred to as a filer. A NAS system presents data in the form of files, allowing consolidation of storage that can be shared by other servers on the network. The simplicity of deployment of NAS as a solution to file services has been very attractive to IT managers regardless of the size of the site. But while managing a few NAS devices is easy, managing many has proven to be challenging and costly.

A single file system that expands to the limits of a server's physical capacity requires a timeconsuming and complex upgrade to a larger server with more capacity. An easier solution is simply to deploy another server or NAS device, which itself eventually becomes a "data island" when the next NAS device is added to the line. When the addition of capacity is multiplied by a large number of NAS devices, administrators must manage each server or NAS device, each with its own file system and each requiring independent manual attention for both file-system and capacity management issues.