FANs of storage arise

File-area networks ease the pain of file sharing, migration and consolidation

Dealing with multiple file servers and network-attached storage filers can be a major hassle. Just ask Harold Russell, a project manager at the Agriculture Department's Food and Nutrition Service (FNS) who works for subcontractor Wyandotte NetTel.

'Moving data from direct-attached storage to a NetApp [fabric-attached storage] box meant going into each file structure and ensuring the correct rights and associations were maintained,' Russell said. 'This was a very manual process and could take several days.'

He turned to file-area network (FAN) technology to virtualize data across multiple file servers and NAS boxes. Result: Instead of several days to migrate files, it takes a little more than an hour.

A FAN is a way to aggregate file systems within a data center so they can be moved more easily and managed centrally. This technology makes sense to anyone who has deployed more than a handful of NAS or file servers in one data center. Each box has its own file system and network connection, so adding another device requires duplicate installation, set up and maintenance functions.

Philippe Nicolas, technology evangelist for FAN solutions at Brocade Communication Systems, said such problems become readily apparent when you have more than five file servers. In addition, one server might be fully utilized while others sit idle, and moving files from one server to another is cumbersome. Further, reconfiguring file systems or making them available elsewhere in the event of a disaster eats up valuable administrative time and effort.

You can solve such problems by adding a logical layer, via a global namespace, between clients and file systems. So activities such as server administration, files reorganization or consolidation can be accomplished without the user noticing anything different. It's business as usual from a user perspective.

FNS uses NetApp Virtual File Manager by Network Appliance for file virtualization, replication, disaster recovery/failover and migration. FNS has eight regions, and each has VFM servers. Two NetApp FAS 250 filers are used at each site for primary storage, and two FAS 270s are used for secondary storage. VFM helps FNS mirror data to the secondary location for disaster recovery.

'Before, we were backing up individual file servers to tape,' Russell said. 'Disk-to-disk backup is far more efficient.'

Each region also has five Hewlett-Packard ProLiant DL 380 and ML 370 file servers. Previously, file management was inconsistent across FNS sites, and failing over posed problems for users in terms of delays and knowing where to find their files.

'Now we can port files to any hardware using a global namespace,' Russell said. 'In the case of an emergency failover, users continue accessing their data as if nothing happened.'

To date, he has not had to deal with a disaster that would highlight the effectiveness of this technology in the real world. But physical testing at each region has demonstrated that the system performs to expectations, he said.

'The VFM global namespace makes it much easier to manage file structures and move data,' Russell said. 'In terms of recovery, we've gone from one to two hours per file server down to 20 to 40 minutes for a primary filer.'

Vendor variations

A cornerstone of the FAN is the global namespace. This virtualizes file management by decoupling data from specific servers or NAS filers to facilitate migration, load balancing and other functions such as replication.

There are a number of vendors in this area along with NetApp, including Acopia Networks, Attune Systems, Sun Microsystems and EMC. (Brocade offers StorageX, which NetApp rebrands as VFM.)

'File virtualization solutions, such as those provided from Acopia, address three key business requirements: the need to consolidate dispersed corporate information onto more easily manageable NAS systems, the need to enable more effective use of business information and the need to reduce the cost of doing business,' said Richard Villars, vice president of storage systems at market researcher IDC. 'The companies we spoke with reported that file virtualization allowed them to reduce storage costs by 50 percent to 80 percent, while improving management efficiency by up to 90 percent.'

Sun has been working to provide a seamless view of data within a hierarchical storage infrastructure. Whether stored on tape or disk, the idea is that the user has the same view.

Sun's solution is SAM-FS, a 64-bit storage file system that provides both disk and tape file system access. The file system is a stand-alone software product that can be implemented with other applications such as e-mail. It sets up the hierarchical structure and integrates this into the e-mail system. In addition, SAM-FS offers continuous automatic backup. Work in progress is captured by the file system and protected in a way that is transparent to the user or application.

EMC, meanwhile, offers several technologies that could loosely be defined as a FAN. Probably the best example is EMC Rainfinity Global File Virtualization. It virtualizes unstructured data environments and moves data (including active, open files) without disruption.


DCMA consolidates

The Defense Contract Management Agency is another fan of FAN. Unlike FNS, however, DCMA doesn't yet make use of global namespace. Instead, it uses NetApp VFM for data consolidation and migration.

DCMA is an independent combat support agency within the Defense Department responsible for ensuring federal acquisition programs are delivered on time, within projected cost or price and meeting performance requirements. In the process, DCMA manages more than 300T of storage.

Recently, the agency consolidated its information technology infrastructure from 18 to two data centers.

This involved a move from more than 500 servers to 350 production servers ' 175 at each site running Windows 2003 in a virtualized environment. Fifty-six file and print servers were centralized into two clustered NetApp Filers. The NetApp FAS3020C and FAS6070C systems ' four physical filers ' are presented logically as two. Each data center uses the 3020C for file sharing, and the 6070C's are in a storage-area network. VFM was harnessed, in particular, to migrate files into the larger NetApp boxes.

'We used to do file migrations manually using a lot of DOS scripts,' said Peter Amstutz, chief of network design at DCMA's Carson, Calif., data center. 'VFM saved us 500 to 1,000 hours of work in moving data.'

He said the agency is looking at implementing global namespace to present all DCMA files within one virtual file structure. Users in Dallas, Chicago or San Francisco will see the same thing, which will make collaboration much easier, because each region would no longer have to use manual drive mapping.

Instead of backing up 18 locations individually, backup is now centralized into the two data centers using software from CommVault. NetApp VFM mirrors data to NetApp R270C boxes using Serial Attached SCSI and Serial Advanced Technology Attachment drives. Eventually, replication will also be done from one data center to another, with VFM harnessed for failover.

A problem with that plan, though, is latency over long distances. Beyond about 1,200 miles, replication and file sharing start to experience delays. Wide-area network optimization technology by Riverbed Technology has been introduced to reduce latency. It will interact with the NetApp FANs ' one in Boston and the other in Carson ' to provide a coast-to-coast file sharing and replication network.

Looking back on his project, however, Amstutz said he has learned that the route chosen by DCMA might not have been the best. He feels that migrating files into two data centers would have been a far less time-consuming task if a global namespace had been deployed in advance.

'NetApp VFM has paid for itself just from the file migration alone,' Amstutz said. 'But if I had it to do all over again, it would have been much simpler to virtualize our file systems first and then migrate.'

Hot area

The FAN, then, has become a hot area in the storage landscape.

During the past two years, most of the innovative but small wide-area file service and networking optimization vendors were gobbled up by bigger networking companies. Similarly, the traditional FAN players have been acquired by the likes of Brocade, Cisco and EMC. That leaves only Acopia and Attune as independents.

Storage analyst firm Taneja Group highlights these vendor consolidation trends as evidence that the FAN market will be one of the fastest growing sectors in storage in the coming years.

'A FAN is ultimately about applying business-level controls and intelligence to files,' said Brad O'Neil, an analyst at Taneja Group. 'This was not possible with block-level data that is necessarily void of business- or application-level context.'

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