Storage Area Networks Help Manage Huge Data Flows

By moving from direct-attached storage architecture to a networked architecture, companies have gained considerable improvements in the performance, flexibility and manageability of their storage infrastructures. While a SAN cant slow down a companys data growth rate, it does provide a mechanism to reduce the overall cost of storage, by providing an infrastructure where current storage resources are more efficiently utilized and centrally managed.

And the benefits gained from implementing a SAN are not limited to just the largest insurance organizations. Nearly one-third of the companies expected to deploy SANs over the next 5 years are smaller companies (fewer than 250 employees) and two-thirds of the companies expecting to deploy SANs have fewer than 5,000 employees.

If anything has limited the faster acceptance of SANs, it is the complexity associated with the technology. A myriad of connectivity components are required to connect the SAN fabric, including servers, switches and storage devices, often products provided by a variety of manufacturers. Integrated together, todays SAN solutions are compelling. However, they are anything but simple to install and maintain.

Consider the SAN to be a highway system through which critical data flowsif the traffic flow is interrupted, due to any number of possible problems including switch failure, router failure, server or storage device failurethere will be a system slowdown, or worse. An interruption in service can cost an insurance company anywhere from tens to hundreds of thousands of dollars a minute, depending on the size of the company and the time of day.

To manage a SAN proactively, it is crucial for organizations to monitor the overall health of the SAN on an ongoing basis, because waiting for problems to occur can result in disaster.

The various components in the SAN communicate by talking to each other in individual conversations or “exchanges.” For example, a server asks a disk if its active, the disk replies “yes.” The server asks the disk for some data; the disk sends it and asks for acknowledgement of receipt. The server sends an acknowledgement, completing the exchange. If something is wrong in the SAN, such as a disk not responding as expected, the conversation will be repeated until a successful outcome is reached, and this repetition can go on for a long time until resolved, taking up SAN capacity and slowing user response times in the process. By closely watching what is going on in the SAN at the level of individual conversations, SAN monitoring products can find problems before they lead to inefficiency or, worse, a crash of the SAN taking the business out of service.

In the multi-vendor makeup of todays SAN implementations, it is often difficult to isolate and diagnose problem areas. Often vendor finger-pointing becomes the rule of the day and inhibits quick problem resolution. Specialist SAN monitoring tools can look at the overall SAN (not individual components), find where problems are coming from and indicate the most efficient way to address them.

With the comprehensive data available from SAN monitoring tools, network managers can easily identify problem areas and perform trend analysis. Better insight into the SANs performance translates into less finger-pointing, quicker problem resolution and more efficient use of SAN resources. The bottom line for companies is improved application performance and SAN uptime, which translates into greater user productivity and higher customer satisfaction.

SANs hold great promise for helping organizations wrestle with maintaining, as well as accessing and securing corporate data. The companies that best manage and take advantage of this data to better understand and serve customers will be those who lead the marketplace.

is vice president of marketing for Finisar Network Tools (www.finisar.com), based in Sunnyvale, Calif. He can be reached at [email protected].

Reproduced from National Underwriter Edition, April 16, 2004. Copyright 2004 by The National Underwriter Company in the serial publication. All rights reserved.Copyright in this article as an independent work may be held by the author.