Wide-area file services: Feeds, speeds and needs

A primer on IT that lets managers efficiently control files from a central site

Local control might be a desirable way to handle some public policy issues, but it isn't always the best approach to managing information technology systems, especially when cost is a concern. Consider the average regional or satellite office. It usually has its own computer server and networking gear, plus a tape backup system to protect locally created files.

Throw in an onsite IT person to handle the care and feeding of these systems, and the costs begin to add up quickly if you have more than a few sites. But now a new group of products from a handful of companies could reduce these expenses by shuttling data created and used in remote offices to a central office, where IT staff can manage it more efficiently using shared computer resources.

Several of the vendors offering these products are new companies, though last year Cisco Systems acquired Actona Technologies, bringing a big name into the fledgling market. The vendors have few government customers but analysts expect that the market will grow quickly as organizations rethink the current practice of giving every remote office its own mini-IT department.

Consider: The problem

High cost is one of the two main problems with having branch offices run their own IT shops.

"The total cost for one file server, a tape drive, the tape media and the administration time can run between $20,000 to $40,000 per year per branch office, about half of that for capital costs and half for management costs," said John Henze, director of product marketing for the caching services business unit at Cisco.

The other big issue, data protection, is harder to put a price tag on until something goes wrong and important data is lost and cannot be recovered. In many cases, the problem occurs when agencies try to rely on non-IT staff to handle nightly or weekend tape backups.

This approach often results in backups that are done improperly or sometimes not at all, said Brad O'Neill, senior analyst and consultant at the Taneja Group. Even splurging for local IT staff is no guarantee that an agency's official backup policies will always be followed. "Once you get more than a few [branch] locations, it's hard to keep up best practices for local backup," he said.

Until recently, only a few good alternatives have been available, O'Neill said. The growth of the Internet allowed for one option to become feasible by consolidating all of the branches' files on a large server in a central office. IT staff could manage the consolidated management workload more efficiently there. Branch office workers would then access their files on this central server via the Internet, securing the connection using an encrypted virtual private network (VPN).

The problem with this approach is apparent to anyone who has ever tried to open or save a file stored on a remote server using a VPN. A file command that might take a few seconds or less to execute when sent across a local-area network to a server in the same office building can often take several minutes or more when the server is a long distance away and connected by a wide-area network such as the Internet.

This happens because the file access protocols most software applications use work by breaking a file command's data stream into many little pieces, each requiring the exchange of a message between the client and server. A simple operation like opening a word-processing file can involve hundreds of client/server messages.

These exchanges happen quickly on a LAN, which has practically no latency, or delay, but they drag out significantly on a WAN because its small amount of latency for each transaction is multiplied hundreds of times over for all the messages required in a single file operation.

Consider: Solutions

The new products designed to overcome these problems are being called wide-area file services (WAFS) solutions, a term that describes what they do rather than a standard or a technique. The concept behind WAFS is not entirely new — branch office files are stored on a central office server and accessed by remote users via the Internet. But they use some new tricks to eliminate the WAN's latency and other performance shortcomings.

The most common WAFS solution, offered by companies such as Cisco, DiskSites, Riverbed Technology and Tacit Networks, involves at least a pair of hardware appliances, which are small rack-mounted servers with pre-loaded WAFS software.

One appliance is deployed at the central data center and connects to the main file server and storage devices located there. The other is deployed at the remote site, which replaces the branch office's local file server and tape system. One central office appliance can support many field appliances, which creates an opportunity to consolidate all field files in the central office.

The appliances use a variety of techniques that vary by vendor to streamline their communication across the WAN, such as eliminating most of the file command message traffic between the appliances, compressing the data that is sent, and caching frequently used files on the remote office appliance. The net result is to provide LAN-like performance via a WAN.

"A 10M [Microsoft] PowerPoint file that usually takes three or four minutes to open over the WAN, we can get it open in 11 seconds," said Chuck Foley, president of Tacit Networks, which counts at least one federal agency among its customers.

Proponents of the WAFS approach cite several benefits from relocating and centrally managing field office files this way:

  • Agency policies for managing and retaining files can be handled centrally, enabling better enforcement.
  • Backups can be done more efficiently on a single large tape system at the central office, instead of relying on separate backup equipment at the branches.
  • Local offices no longer need to buy and maintain their own servers and tape systems, yet workers still get equivalent service and performance in terms of file access and data protection.

A slightly different take on the WAFS approach is offered by Signiant, which sells software that is loaded on servers at the customer's central and remote offices. The software leaves local office files on the local office's servers, but provides policy-based copying of that data to a server based at a central office for consolidated management and backup, receiving benefits similar to those gained from other solutions.

Besides using the software for consolidating file backups, some Signiant customers, including a few Defense Department agencies, also use the software to distribute files from central offices out to the field.

"They like the policy-based controls for transferring synchronized operational files to remote offices, often over very long distances," said Jeff Forte, federal account executive at Dataline, an integrator that has sold Signiant software to the DOD.

Consider: Purchase and deployment

Like companies selling new technologies, vendors in the WAFS market tend to be smaller and have shorter track records on important issues such as customer support. However, this has not deterred some high-profile corporate customers, including a number of the world's largest banks, from signing on with WAFS vendors, O'Neill said.

He advises prospective customers to expect more market changes akin to Cisco's acquisition of Actona. "I think you will see massive consolidation among vendors," he said. "Most of these guys will become puzzle pieces for other companies."

O'Neill also recommends testing the WAFS approach in a limited setting to understand the operational implications before rolling it out on a more widespread basis. "It can be very disruptive to the local office infrastructure," he said.

Wide-area file services products

What you will need:

The most common solution involves placing one hardware appliance at a central office and at least one appliance at each satellite office. At the satellite offices, the appliance replaces the local server and storage. Software-only versions of the solution, such as the one from Signiant, require loading the wide-area file services (WAFS) software on an existing server at a central office and on branch office servers. The Internet typically serves as the wide-area network, with data transmissions secured by a virtual private network product, purchased separately.

What it will cost:

  • Cisco's File Engine appliance, which can be used at a central or remote office, lists for $12,000 and includes a 50-user software license. Additional 50-user licenses cost $4,500. Total entry-level cost: $24,000 for a minimum of two appliances.

  • Tacit Networks uses a remote user-based pricing model for its WAFS product. The branch office appliance starts at $7,500 for a 10-user license; the central office appliance costs $15,000. Total entry-level cost: $22,500.

  • Signiant's Mobilize software-based solution starts at about $55,000 for a typical installation, including central and branch office software.

    — John Zyskowski

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