Method and apparatus for reducing response time in automated library data retrieval systems

摘要

Access time is improved in a automated library system having sequentially stored data on a recording tape medium. A multiplicity of copies of the data is stored on different tape cartridges. The copies and the original are stored in different areas of the library. Each data segment stored on the tape media copy is stored in different areas of the media length from the original. The multiple copies are created and deleted independent of any user control. The usage of the original and any copies determine the number of copies and their residence times. The library manager selects the tape cartridge that can be retrieved in the shortest response time using the location of the original and the copies, the location on each cartridge of the data requested, the drive and library robot picker availability and the respective queues.