In recovering from an IT disaster, timing is everything. Costs can mount quickly with each minute that access is denied to critical systems, networks and data. That's why it's essential to have a plan for getting your data back -- whether that means replicating your entire network or just the critical pieces of it, using company-owned or outside resources.

Disk-to-disk-to-tape (D2D2T) Data is initially copied to backup storage on a disk storage system and then periodically copied again to a tape storage system . Many businesses have done backup directly to relatively inexpensive tape systems. For many computer applications, it's important to have data immediately ready to be restored from a secondary disk if and when the data on the primary disk becomes inaccessible (for example, if the server fails). The time to restore data from tape would be considered unacceptable. On the other hand, tape is a more economical alternative for long-term storage (archiving). Because it's also more portable, tape is often used for off-site backup and restoration in case of a disaster.