CHICAGO -- Everyone knows that mirroring data to multiple devices is a must for high-availability, but with disk drive technology becoming more and more reliable, is mirroring really a necessity? According to users and experts here at the Storage Decisions 2002 conference, the answer is a resounding yes.
"Mirroring and RAID were created because disk drives don't always work," said Richard Scannell, vice president of strategy for GlassHouse Technologies Inc., Framingham, Mass. In addition, he said, "now threats from terrorism and corporate espionage threaten data."
Even though disk drive technology has become more reliable, the experts believe that putting all of your proverbial eggs of data in one device or at one location is business suicide.
Drive reliability will not eliminate the need for mirrored copies, Scannell said. Rather, this factor, along with dropping prices, might make the process of remote mirroring, or the practice of duplicating data in separate volumes on two hard disks to make storage more fault-tolerant, an even better option than before.
"The cost of capacity has collapsed," he said. "If people use cheaper [target devices] for mirroring, they won't care as much about the target as they will the transport mechanism they use to get the data there."
Few organizations needs to be up and running as much as a hospital and, as a storage engineer for GE Medical Systems Inc., Mt. Prospect, Ill., Maqbool Patel needs his eight terabytes of medical images online.
His company is considering creating a remote data center location for the purpose of mirroring its medical data. Patel is considering using a smaller target device, such as an LSI Logic storage system, to mirror the data from his EMC storage arrays. All these changes are under consideration because of the newfound interest in disaster recovery that Patel is seeing.
"The first question asked by the customer we're dealing with now was, 'What is your DR plan?'" Patel said.
Patel said that designing a remote mirroring plan would involve prioritizing his stored files. He said medical imagery is accessed frequently in the first six months of its life cycle, but that demand drops off over time. Luckily, he said, GE Medical Systems still has time to come up with a plan.
"It's a matter of prioritizing what you're mirroring. You have to make sure you know what you're putting across the wire," said Jamie Gruener, senior analyst for the Boston-based Yankee Group.
There is some risk involved in mirroring data from one array to another from a different vendor. Gruener said that with different targets, you can't be sure which data has made it to the remote location.
"If you're centralizing management to where you want to manage what's on both sides of the wire, most people want to know that the data got there, and that it's useful," he said.
According to the analysts, the practice of data mirroring will be around for a long time to come, regardless of whether its popularity is dictated by shaky technology or terrorist threats.Let us know what you think about the story; e-mail Kevin Komiega, News Writer
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