Continuous data protection (CDP) has languished despite its benefits over traditional backup methods. Storage managers are concerned about the additional overhead it would entail and its "lack of integration with their other data protection software such as backup, replication, snapshot, etc.," says Marc Staimer, president of Dragon Slayer Consulting, Beaverton, OR. Still, there are signs CDP may be making some inroads in the data center.

"Email has become such a huge repository for all types of information and data exchange," says Nate Buscher, director of IT at Sidney Kimmel Cancer Center (SKCC) in San Diego. "We needed something even more disaster-proof than nightly backups."

Buscher deployed TimeSpring Software's TimeData to protect the center's Exchange data, saving all changes to a repository in another building on its campus. SKCC has used TimeData for more than two years and "in that time it has saved our butts twice," says Buscher. In one case, misconfigured antivirus software corrupted the Exchange database; Microsoft called it a "lost cause," but Buscher used TimeData to roll back to an earlier version and restore the system.

EvensonBest, a New York City office furniture dealer, also experienced a corrupted Exchange message store. "We had done all the good things that people are supposed to do," including backing up the database several times a day, says Martin Silverman, the firm's IT director. But restoring from tape would have taken hours. "For us, that was a wake up call," says Silverman. EvensonBest chose XOsoft WANSyncHA (since acquired by CA), and now uses it to protect approximately 75% of its applications.

Maimonides Medical Center in Brooklyn, NY, which employs both a picture archiving and communication system (PACS) and a video surveillance application, needed to shorten backup windows and speed up recoveries, notes Carlos Cabrera, manager of enterprise systems. To do that, says Cabrera, the center uses DataCore Software's Traveller CPR CDP product, which is then backed up using IBM's Tivoli Storage Manager for extra protection. "Eventually, we'd like to do our daily backups through CDP and then grab the image and back up from the CDP system," he says.

CDP becomes more viable when data protection issues are addressed on an application-by-application basis. Still, Staimer says users should weigh "the trade-offs in protection--RPO [recovery point objective] and RTO [recovery time objective]--vs. operational integration with the entire data protection strategy."

--Rich Castagna