File virtualization products have come about because of a common pain point with NAS systems: file system size limitations. Many traditional NAS devices, such as NetApp Inc.'s filers, as well as individual servers that serve as NAS storage, have upper limits between 2 TB and 16 TB. As file data grows, these limitations mean lots of painstaking storage management to keep capacity balanced on multiple NAS systems.
File virtualization vendors have taken two paths to address that issue, according to ESG analyst Brian Babineau. In the past year, some of the more high-profile file virtualization products have added a layer of abstraction that allows storage administrators to manage multiple existing heterogeneous NAS devices from one console. Other vendors have chosen to provide a virtual file system known as a global namespace, which pools data from individual NFS or CIFS devices together. Some of these products also provide NAS connectivity to block-based SAN systems.
The file virtualization marketplace has seen some consolidation lately, with some of the startups that began making a name for themselves over the last two years being snatched up by larger vendors. Several of these vendors in turn have repackaged those products to make this type of file virtualization a feature of a networking product or to better target offerings around data migration, which so far has been the most popular use case.
The few players left in this market are listed below, along with thumbnail descriptions of their products' functionality and history.
Vendor Name: Brocade Communications Systems Inc.
Product Name(s): StorageX; File Management Engine (FME) Brocade branched out from SANs into file virtualization with the acquisition of NuView in March 2006. The first product to spring from that merger was StorageX, an out-of-band Windows file virtualization software product.. Brocade reports 600 users of StorageX as well as reseller deals with IBM, NetApp and Hitachi Data Systems. StorageX uses an embedded Windows Server 2003 operating system.
Brocade's newer File Management Engine (FME) sits in the network and automates migrations of locked and open files according to policy. While the StorageX software can manage files down to the folder level, FME can manage individual files because it sits in the data path.
Vendor Name: EMC Corp.
Product Name(s): Rainfinity Global File Virtualization; Rainfinity File Management Appliance
EMC was the first major vendor to make an acquisition in this space when it bought startup Rainfinity in 2005. EMC's Rainfinity products are attached to an intelligent network switch and can move in-band and out-of-band, depending on their function. The File Management Appliance, a pared-down repackaging of Global File Virtualization, was announced last year to refocus the product around data migration. Rainfinity uses a proprietary Linux-based OS.
Vendor Name: F5 Networks Inc.
Product Name(s): F5 Acopia ARX series
Networking specialist F5 Networks bought Acopia last October for $210 million, with the goal of adding file system management to its existing networking products. So far, F5 has added virtual heterogeneous snapshots to Acopia's system, meaning the system can instantaneously create a snapshot across multiple NAS devices from different vendors. Those snapshots are still limited to EMC Celerra and NetApp FAS storage systems. Acopia uses a proprietary operating system called FreedomFabric OS.
Vendor Name: Attune
Product Name(s): Maestro File Manager
One of the last independent file virtualization vendors left, Attune's claim to fame is a hardware appliance that can move in-band or out-of-band. The device is based on an embedded Windows Server 2003 operating system and can also offer heterogeneous snapshots.
Vendor Name: Njini
Product Name: Njini Information Asset Management Suite
Njini's software receives all file operation requests, such as open, close and save, by NAS protocols such as CIFS and NFS, and maps these protocol operations to a virtual file system, including data classification information to manage each file according to policy.
Cisco Systems also acquired a file virtualization software startup, NeoPath Networks, in 2007, but it immediately took the NeoPath File Director products off the market. They have yet to be re-released, and Cisco has been vague about its plans for the Linux-based in-band systems.
Players in the global namespace marketplace include makers of clustered NAS systems, such as Isilon Systems and OnStor. SAN file system vendors including Ibrix and Quantum . (with the StorNext filesystem it acquired with ADIC) and high-performance NAS vendors including Exanet and Silicon Graphics. Microsoft also has its own global namespace software for Windows systems, formerly known as DFS and now known as DFS Namespaces. (See our special report on high-performance NAS.)
Babineau predicts that the two product categories in file virtualization will converge as file storage continues to grow. "These two tracks in the market both have longevity just because of the amount of data that's going to be stored as files keeps growing and growing, and we're seeing more and more money fly that way," he said. "There could be collisions along the way."
Go back to the beginning of the File Virtualization Special Report.