2006 may well be the year of NAS optimization according to recent findings from TheInfoPro (TIP), www.theinfopro.net, as the latest wave of TIP's ongoing storage study shows file virtualization evolving from "nice to have" to a permanent spot in the file-handling toolbox. In fact, in TIP's proprietary Storage Management Technology Heat Index(TM), file virtualization rated higher than block virtualization. The Heat Index prioritizes over 20 different storage management technologies (including file and block virtualization, continuous data protection (CDP), storage security software, disk to disk for backup, storage resource management (SRM) and automated storage provisioning) based on user-reported plans for spending and implementation. These study findings are based on interviews with 155 Fortune 1000 storage professionals, drawn from a variety of industries.

Regulatory compliance has created two major problems for storage professionals: more and more data must be stored and retention times have changed from days to forever. To help store the increasing data files, NAS footprints have tripled over the last 18 months, going from an average of 50 terabytes to close to 150 terabytes, creating a management issue that file virtualization helps simplify. Robert Stevenson, Managing Director of TIP's Storage Research says, "It is wonderful having one or four NAS filers but having 20 creates a major management issue. Getting the most from a NAS investment requires optimization and that's where file virtualization helps."

Early file virtualization products were software-based but appliance solutions are becoming increasingly common. Choices abound: key vendors include EMC's Rainfinity Global File Virtualization, NetApp's V Series, Acopia's Adaptive Resource Switch and NeoPath Networks' File Director. Global/cluster file system vendors include Sun's QFS, IBM's SFS, IBRIX, Isilon, PolyServe, Pillar Data Systems, ADIC, Symantec's VERITAS Storage Foundation Cluster File System, Lustre, Panasas, HP's StorageWorks, ONStor and DataCore. Brocade's recently-acquired NuView and NSI Software also approach file virtualization, and Microsoft's System Center Data Protection Manager has file virtualization potential.

Block virtualization, on the other hand, is nothing new, but has moved slower than file virtualization, delayed by concerns about where it would live - in the switch, the host, the frame or a separate appliance. Now that appliances and storage arrays have emerged as the way to go for block, interest is heating up but corporate IT structure will slow deployment. Because block files tend to be large and tied to specific applications, implementing block virtualization requires a strategic investment and careful planning across multiple IT teams to avoid disruption.

Vendors on the block side are EMC's Invista, IBM's SAN Volume Controller, HDS's TagmaStor, Sun's StorageTek 6920, Cloverleaf, FalconStor, StoreAge, Incipient, Xiotech Magnitude 3D, NetApp and Symantec.

Differentiating file versus block virtualization, Stevenson observes "Block virtualization is open heart surgery; file virtualization is LASIK. File virtualization is easier, faster, and less invasive, with less interruption to storage availability."