File virtualization products are software-based tools, although sometimes delivered as appliances. Their original goal was to provide scale-out manageability of multiple traditional NAS systems by layering a third-party's global namespace over existing NAS nodes. In 2006, file virtualization topped market research firm TheInfoPro's annual survey of "hot technologies" among Fortune 1000 companies.
File virtualization products are still on the market, particularly F5 Networks' ARX switch that F5 acquired by buying startup Acopia Networks in 2007. But other file virtualization players that entered the market with Acopia, including NeoPath Networks and Attune Networks, have vanished.
EMC Corp.'s Rainfinity file virtualization product has been refocused as a data migration add-on for tiered storage and archiving with EMC's Celerra NAS products.
Aside from F5's ARX and EMC's refocused Rainfinity, there's AutoVirt Inc.'s eponymous software still standing among five virtualization products. AutoVirt targets small- and medium-sized Windows shops as an alternative to Microsoft's Windows Distributed File System (DFS). NetApp Inc. also offers the V-Series virtual NAS gateways, but these don't yet offer a global namespace.
"It's tough to go buy an expensive NAS system with intelligence built in, and then lay file virtualization from someone else over it," Forrester Research senior analyst Andrew Reichman said of the earlier generation of file virtualization products. "Some financial services customers did seem to buy, but file virtualization seems to have plateaued as cluster vendors get more ability to set up different zones with various disk and performance densities as part of the NAS system."
Is file virtualization headed for the cloud?
While the file virtualization market never bloomed, it's not quite dead yet. One large national law firm based on the East Coast has used AutoVirt's AutoClone replication software to migrate data from legacy Windows servers to an EMC Celerra NAS system. AutoClone uses Microsoft APIs to integrate a proprietary global namespace with Microsoft's Domain Name System (DNS) server. The global namespace abstraction between the user and the file server means files can be moved to back-end storage without requiring updates to links or shortcuts. AutoClone supports policy-based file migration.
R. Craig Dodson, senior infrastructure architect for that law firm, which he asked not be named because of internal policy against publicly endorsing any vendor, said AutoVirt's integration with DNS also intrigues him for disaster recovery. However, Dodson said AutoVirt's core file virtualization product, which uses global namespace for day-to-day file management, remains in his test and development lab because of incompatibility with his Celerra filer.
"They don't currently support my Celerra NAS devices because of the way I have it configured," said Dodson, who uses Celerra in a high-availability (HA) pair with virtual data movers. AutoVirt officials acknowledged this, and said through a spokesperson that it's working with Dodson to resolve the issue.
What makes Dodson stick with AutoVirt? "The reason I still talk to these guys is that I like the direction they're going to go in, it looks like it could be a good replacement for DFS," he said. While Dodson acknowledged he's also kept up with alternatives like scale-out NAS systems with their own native global namespace, software that layers over multiple devices looks more cost-effective than migrating all NAS data to a scale-out system for now.
Other organizations have found that a combination of F5's ARX and data deduplication devices a good way to cut costs with tiered storage. F5 officials said the company saw a 60% year over year increase in ARX sales between 2008 and 2009.
"We have seen the target customer profile expand beyond large enterprise to encompass mid-sized enterprises as well," wrote Nigel Burmeister, F5's director of product marketing, in an email to SearchStorage.com. "We have also witnessed increased diversification in verticals moving beyond initial success in financials. Automated tiering/archive has increased in importance and we have also seen a trend toward greater diversity of storage in customer environments, moving beyond the traditional Fibre Channel/SATA mix to include technologies like deduplication, SSD [solid-state drives] and organizations beginning to consider cloud storage."
Some analysts see the cloud as the ultimate destination for the remaining file virtualization players, as well as for emerging products that can serve as gateways for consolidated management of on-premise and cloud data storage. Newer companies in this space include Nasuni Corp. and Avere Inc.
Terri McClure, a senior analyst at Enterprise Strategy Group, said these new players, with their focus on high performance, could find a niche "in repurposing low-end NAS to more demanding performance tiers or saving people money by tiering to the cloud."