Active Archive: Front-End File System For Tape And Disk

By Spectra Logic Corporation

Tape has come back into its own, with the advent of new hardware and software that lets tape act like disk. This completes the cycle, with tape initially used like disk for mainframes. In that context, tape served as storage of data to be acted on, and was loaded into the computer only for manipulation. In the 1960s disk became an affordable technology that was used in place of tape for storing data. Tape moved to the role of data backup medium given its long archival life, low cost, and low maintenance, low-energy use. Then disk was used as tape by way of VTLs. Now the cycle is complete, through the use of active archive applications that put a file system in front of tape.

The latest change in the cycle of disk/tape usage started in about 2004, when VTLs entered into wider use for backup. Diskas- tape moved disk into the spotlight. Disk steadily continued its role in data storage, with less expensive SATA disk providing relatively cost-effective shortterm storage.

Then disk vendors started pushing disk as the only storage medium organizations require, given its relative simplicity once it was installed on a site. But the economy, disk's true high cost in terms of initial purchase price and over the life of the product, the intensive power use disk demands and associated costs, and the green IT movement with an emphasis on reducing power use all helped to focus attention on cost. This drew attention back to tape.