Getting more than storage out of your SAN

Worldspan uses XIOtech's SAN to upgrade servers quickly and improve server data protection.

By Suzanne Gaspar
Network World, 08/21/00

Turning a 32-hour Novell server upgrade into a four-hour job with no user downtime was easy for Mike DiBernardo.

DiBernardo says the XIOtech storage-area network (SAN) he installed last year affords his IS team the ability to upgrade servers quickly, improves server data protection and consolidates storage for the company's 15 servers.

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As a senior vice president of worldwide technical operations at Worldspan, a travel reservation services company in Atlanta, DiBernardo is responsible for upgrading 15 servers, each loaded with 30G bytes of data. Together, the servers support a total of 3,000 business-critical users across the Novell server complex. Last December, he installed a XIOtech SAN system consisting of a Magnitude Fibre Channel Disk subsystem, a Vixel Fibre Channel switch and XIOtech's Fibre Channel adapter cards, into Worldspan's network as a means of making the upgrades much less time-consuming. This new product stores user data on the company's SAN as opposed to the server, saving time, money and aggravation for server management.

Despite the fact that DiBernardo purchased the system to help with upgrades, the SAN currently mirrors data across its Novell servers at Worldspan's Atlanta headquarters, consolidating storage for the servers and providing redundancy for data integrity. A similar implementation is in progress at the company's Atlanta and Kansas City data centers. While the SAN implementation has currently realized only soft cost savings, DiBernardo expects hardcore savings to come to light with the next server upgrade because he will only need to buy the minimum amount of disk storage on each server to accommodate the NOS. The remainder of the data will be stored on the XIOtech machine, which is configured to hold up to 1 terabyte of data.

DiBernardo says his IS staff can now purchase servers such as the new 1U-high models that Compaq and other vendors are offering. The servers cost approximately one-third the cost of a full-blown server. Without the disk storage element, the 1U-high servers are one unit of rack measurement high, as opposed to a traditional server with disk storage that measures 20 units high. With its small footprint, a data center can hold up to 30 1U-high servers in a rack as opposed to just three traditional servers.

Easier upgrades

Server upgrades previously required three to four engineers working on the weekends and required a lot of time, as they needed to copy 30G bytes of data over the company's 100M bit/sec LAN to new servers. Now upgrades can be completed in minutes, DiBernardo says. The time needed to configure the servers, load NetWare and other applications, and transfer all the data - which used to average 20 hours per engineer, per server - has been reduced to two hours per engineer, per server. Worldspan has no plans to reduce its number of staff but will dedicate the network engineers' time to other important tasks such as application integration, network monitoring and end-user support. For future upgrades, IS can choose high-powered servers requiring no disk space purchase - an overall lower-cost implementation that will allow the company to spend its hardware dollars on faster processors instead of disk storage.

Still, DiBernardo says additional savings will be realized with an upcoming migration to NetWare 5.1 and the use of server clustering. IS has plans to implement Novell clustering, but in order to do so it needs to implement NetWare 5.1, a large undertaking expected to be completed before year-end.

And because clustering is not an option until the NetWare 5.1 upgrade is complete, the cost-saving benefits of using SAN technology are not being fully realized at this time. However, the redundancy of hot-standby servers provides far more reliability in uptime, DiBernardo says.

Aside from the reduced personnel costs required for upgrades and future anticipated hardware savings, the price of the XIOtech SAN system was significantly less than its competitors, DiBernardo says. This factor saved Worldspan money on the initial implementation, he adds.

To select XIOtech's SAN system, DiBernardo studied Gartner Group reports and various trade magazines, attended multiple seminars and used value-added resellers and industry contacts. He also consulted with Novell technical contacts and network engineers from other corporations who had opted for SAN gear. IS looked at gear from Clarion, Winchester, Network Appliance and Hitachi, in addition to XIOtech. All the other SAN systems were more expensive and limited in their support of Novell File System, he says.

DiBernardo admits the other SAN products did offer significant cost savings and performance and reliability improvement over individual server storage, but when it came to Novell compatibility issues, he says XIOtech's was the only SAN to fit the bill. He really liked the fact that his IS team could expand the NetWare volume size on the fly to tactically add storage to various server assets when needed. He says the Magnitude-to-Magnitude mirroring feature for disaster recovery was also a strong selling point.

To date, Worldspan's SAN implementation has been fairly straightforward, however IS initially dealt with some server abends, which they were able to trace back good old-fashioned conflicting IRQ settings on the XIOtech adapter cards.

"A SAN needn't be a major strategic decision that you should put off," DiBernardo says. "It can also be a very sound tactical implementation to address capacity planning issues, server performance and the ability to upgrade servers quickly."

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