Keeping a Safe Distance

IP storage allows long-distance data replication and recovery, but the technology is emerging slowly.

Hurricane Isabel and the fires that recently devastated Southern California have provided storage managers with more evidence that it's a good idea to back up data to a second data center scores or even hundreds of miles away.

To keep the costs of replication affordable, a handful of banks and brokerages began testing long-distance IP replication for data recovery two years ago, and interest in the technology has grown among other types of businesses since then.

Even though long-distance IP storage is now available, some storage managers still resort to bulk replication on tapes, which might be sent overnight to a remote site for safekeeping. But managers usually prefer keeping replicated data on storage disks for quicker recovery. "Recovery from tape is too laborious," says Robert Gray, an analyst at market research firm IDC.

A dedicated optical or copper connection between data centers could be used for replication but would be costly to lease from a carrier and prohibitively expensive to build privately, Gray says.

Users of IP for long-distance storage have found that a conventional Internet connection can be used for e-mail and other purposes during the day and as a replication highway at night or at other low-traffic times, Gray says. The only added cost is for a switch, available from several vendors, that converts data on the Fibre Channel storage protocol to IP using the Fibre Channel over IP (FCIP) protocol. The pipes between primary and secondary storage facilities can be fiber, copper or even wireless, depending on the distance.

The use of IP in long-distance storage is really just starting, despite the deployments that were publicized two years ago, says Steve Duplessie, an analyst at Enterprise Storage Group Inc. in Milford, Mass. The 2003 market for switches and related gear to convert Fibre Channel to FCIP will be about $100 million, with 90% of that total shared among McData Corp., Cisco Systems Inc. and Computer Network Technology Corp., he says. There are probably 500 implementations of long-distance IP replication under way or up and running, Duplessie estimates.

Close Calls

Steinbach Credit Union in Steinbach, Manitoba, in January began setting up an IP-based data recovery center in Winnipeg, 35 miles away, says network administrator Denis Van Dale.

The credit union, which has 35,000 customers, decided to spend $350,000 (Canadian) to do replication at a remote site in the summer of 2002 after two power outages during thunderstorms that left water in the basement of its offices, Van Dale says.

"It could have been a disaster of major proportions," with potential damage to the tape backup system, he says. When he learned that a branch office was opening in Winnepeg, it became the logical choice for replication. The backup center was ultimately reached via wireless IP, using high-speed radios at each end and a transmission tower midway between the two sites.

The project provides real-time backup of all data in addition to disaster recovery. The wireless Ethernet connection has saved the credit union about $50,000 (Canadian) per month compared with a wired connection, and there are administrative savings as well, so the return on investment will be reached in about a year, Van Dale says.

Steinbach uses IP switches from Nishan Systems Inc. (which was purchased by McData in September), clustered storage gear from Xiotech Corp. and radios from Proxim Corp., Van Dale says.

Taking a different approach, the Cancer Therapy & Research Center in San Antonio 18 months ago began replicating data over IP to a research facility 22 miles away, in another part of San Antonio, via an optical connection.

The research center setup uses Cisco storage routers that connect to a storage-area network using Fibre Channel Clariion disk arrays from EMC Corp., according to Chief Technology Officer Mike Luter. The optical connection had been used for IP telephony and data applications before the replication began, he says.

Luter says that "the ROI is not really in dollars but in patient care," which is enhanced because there is very little delay if a server fails -- perhaps only 10 minutes, compared with hours before the data recovery project was completed. "We're able now to ensure we don't interrupt treatment," he says.

Some companies have ambitious plans for the technology. For example, Sprint Corp. in July announced a prototype of a storage network over FCIP from Overland Park, Kan., to Burlingame, Calif., and back to Overland Park, a total of 3,600 miles. The pilot used Hitachi Data Systems Corp. storage and Cisco SAN switches and was designed to show that Sprint could offer such a service to customers at "much less cost than running dedicated, single-purpose fiber," says Ray Dickensheets, a member of Sprint's technical staff. The network won't be limited to fiber-optic cable and could run over copper circuits, he says.

"All these efforts are aimed at getting replication outside a metro area," says Dickensheets.

Special Report

The New Rules of Storage

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Copyright © 2003 IDG Communications, Inc.

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