The emergence of file virtualization products is the result of poor NAS management. NAS boxes lacked central management, and it was difficult to access files on all of the storage connected to NAS.
"For years users said, 'My first NAS server is great, but by the hundredth [NAS server], it becomes a major headache,'" said analyst Arun Taneja, with the Taneja Group.
This management headache brought about products that helped file virtualization catch on before block virtualization, which still gives many storage administrators pause. This is reflected in acquisition activity that began a few years back and in recent surveys that suggest file virtualization could become mainstream soon. EMC Corp. started the mergers and acquisitions in this space by acquiring Rainfinity in 2005. Since then, Brocade Communications Inc. picked up NuView in 2006 and F5 Networks Inc. bought Acopia last year. Attune Networks Inc. is another player in the file virtualization space.
A SearchStorage.com/Storage magazine survey found that few users have already deployed file or block virtualization, but 55% said they planned to deploy or evaluate file virtualization this year.
According to a 2007 survey conducted by TheInfoPro of more than 200 enterprise and midmarket organizations, 18% already have file virtualization, and another 16% were either evaluating it or planned to do so by the end of March 2007. Forty-seven percent of those surveyed by TheInfoPro expected to at least evaluate file virtualization by the end of 2008.
File virtualization appliances create a layer between the file servers and the client boxes that access them. The layer manages files and file systems across servers, presenting client boxes with one logical file mount for every server, while the servers host the file data and metadata. A key component of file virtualization is the global namespace, a place to index files on network file servers so files can be shared between file servers.
File virtualization technology is maturing, and vendors are rolling out features, such as heterogeneous snapshots. Attune added this feature in 2007 and Acopia followed suit this year.
File virtualization is beneficial to any shop suffering from file sprawl, not just shops with hundreds of NAS servers. The school district in Temple, Texas, uses Attune's file virtualization product, called Maestro File Manager, to reduce its storage footprint, minimize duplicate file, archive older data to lower cost storage and provide a central entrance point in the district through global namespace. And, the school district doesn't even have networked storage, only DAS on servers.
"We have a lot of servers and a lot of space, but it's hard to manage that effectively," said John Greiner, network supervisor. "Now we have one place where all users can find their files. We created the global namespace, called District, where anybody can go to find data."
Greiner said after implementing Maestro File Manager, the school district was able to archive 4.9 million files -- more than 86% of the district's files -- that had not been accessed or modified in six months.
And now that file virtualization is no longer an emerging technology, organizations aren't waiting for file sprawl to implement it. They're increasingly using file virtualization appliances as they install NAS boxes to keep things from getting out of hand, said Chris Lynch, F5's senior vice president of data solutions. That's especially the case, he said, if the organization uses more than one storage vendor.
"Starting out, most customers were bringing us in after the fact to help with management," Lynch said. "Now they're bringing us in early."
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This was first published in April 2008