The virtual tape server (VTS) system (not pictured) in an ATLDS
combines the random access and high performance characteristics of
DASD with outboard hierarchical storage management and virtual tape
devices and virtual tape volumes, providing significant reductions
in the number of physical cartridges, devices, and automated libraries
needed to store customer data.
The key concepts of this system are as follows:
- Emulating 3490-type tape devices (virtual devices)
- Emulating 3490-type tape volumes (virtual volumes)
- Import and export functions
- Tape volume cache
- Storage management of the tape volume cache
- Improved cache management
- Deleting expired virtual tape server logical volume data
- Maintaining data fragments from migrated volumes
- Fast response for nonspecific mount requests
- Use of the IBM Enterprise Tape System 3590 and 3592
- Automatic 3590 and 3592 storage capacity utilization
- Logical library partitioning
- Operator interface with the library manager
- Logical volume inventory
- Physical volume pooling
- Selective dual copy