An automated tape library dataserver (ATLDS) consists of tape drives, tape cartridges, a tape cartridge storage area, input and output stations for inserting and removing cartridges, and a mechanism for moving tape cartridges among these areas. The volumes within an automated tape library are known as library-resident tape volumes. Tape volumes can also be located on shelves outside the automated tape library. These volumes are known as shelf-resident tape volumes. See Figure 1 and Figure 1 for examples of the IBM TotalStorage Enterprise Automated Tape Library (3495) and the IBM TotalStorage Enterprise Automated Tape Library (3494).

Tape cartridges are stored and retrieved by an automated cartridge accessor. The cartridges are placed in an input station by the tape library operator. The cartridge accessor then scans the external volume label on the cartridge, carries the cartridge to the appropriate storage location, and places it into the library. When a volume mount is requested, the cartridge accessor retrieves the cartridge from the storage location, carries it to the requested drive, and mounts the cartridge in the drive. Upon completion of the tape operation, the tape cartridge is unloaded, the accessor retrieves it from the drive, and returns it to a storage location in the library.

However, the tape library operator can continue library operation during periods when the cartridge accessor is not operational. During this time the operator responds to commands displayed on the manual mode console. This is known as manual mode operation.

In an ATLDS environment, mount and demount messages are only issued to the system log and will not appear on the console.