The IBM Virtual Tape Server: Making tape controllers more autonomic

The IBM Virtual Tape Server provides a revolutionary tape storage solution that emulates tape drives using a disk cache, providing up to 256 virtual tape-drive images and stacking the virtual tape volumes onto a maximum of 12 physical tape drives. The high ratio of virtual to physical drives, combined with the stacking of virtual volumes, provides tape storage that is both cost- and space-efficient. Existing IBM products are used as microcode building blocks to provide the core functions of the virtual tape server. These core functions are integrated into a reliable, high-performance storage subsystem by autonomic computing controls.