Prioritize for recovery
"First things first" is the key operating principle when recovering from a data loss, whether due to a hardware glitch in a storage subsystem or complete destruction of the enterprise data center. However to apply the principle effectively you must know your priorities. At least as importantly, you have to work with users to set those priorities.
If you suffer a major disruption, you're unlikely to be able to bring everything back on line at once. Deciding who comes back in what order will depend in part on how severe and how extensive your loss is and (usually) on pre-arranged disaster recovery plan. Since how fast you can come back depends in large part on how much money you're willing to spend to protect each resource, this decision has economic consequences as well. For example, critical databases can be remotely mirrored (as well as being backed up) to minimize recovery time, but that effectively doubles the cost of storage capacity for those databases.
It's vital that you set your recovery priorities in close consultation with your users and other affected parties in the enterprise. In the case of disaster planning, the storage and IT part of the plan will have to mesh closely with the disaster plan for the entire organization and quite possibly third parties such as suppliers and communications vendors.
Rick Cook has been writing about mass storage since the days when the term meant an 80K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
This was first published in January 2002