Baseline has an article on Best Practices in Disaster Recovery, Business Continuity Planning. "... disaster recovery priorities depend on the nature of the system. 'We take snapshots ranging from every hour to every 15 minutes, depending on our systems,' says Wolfgang Goerlich, network operations and security manager for the Birmingham, Mich.-based investment banking firm. 'Our top-tier systems, such as trading, can have an issue if we lose even 15 minutes. Lower-tier systems, such as research, just generate reports once a day, so if they lose data for [a few] hours, it isn’t as big of an issue. With our lowest-tier systems, our DR plan is to go out and buy boxes and bring them up in a couple of weeks.'"
"The key thing for us was a very short recovery-time objective,' says Goerlich. The firm uses Compellent’s virtual storage arrays, with the DR baked in. He says it takes just one click to activate DR and boot up the systems on a new box."