IBM has a new virtual tape drive management system for mainframes that compares to similar technology introduced last spring by rival Sun.

The IBM System Storage TS7700 Virtualisation Engine is the successor to its TotalStorage Virtual Tape Server and offers increased capacity, faster processing speed and improved disaster recovery features.

Because copying batches of data onto a tape is a time-consuming practice, tying up server operations, virtual storage systems save the data into a disk cache for transfer onto tape at a later time. The TS7700 offers 6TB of disk cache storage capacity, a four-fold increase over the 1.5TB of cache in the previous model, said Cindy Grossman, vice president of IBM tape storage systems. An available 3:1 data compression ratio further expands capacity.

Since the 7700 operates in a grid computing environment, it can simultaneously copy data to two different tape storage sites for improved disaster recovery, said Grossman. Data can be "mirrored" to multiple sites and the system will know where to find it.

IBM's announcement follows a similar product launch from Sun. In May, Sun updated its Sun StorageTek Virtual Storage Manager System, a tape drive manager also for mainframe environments, which also stores data in disk cache for later copying onto tapes and offers double the capacity and performance of its previous generation technology. Sun acquired StorageTek in 2005.

"These products tend to leapfrog over one another," said Mike Kahn an analyst with The Clipper Group. Enterprises are looking to use their tape storage networks better. Storing data to a disk and then later to tape gives enterprises storage flexibility. The virtual tape storage market for mainframe systems is a two-company market, of Sun and IBM, he said.