User's Manual

Configuring and Operating the DLT4500 Mini-Library
4-2 DLT4000/DLT4500/DLT4700 Cartridge Tape Subsytem
4.2 Introduction to the Mini-Library
The mini-library includes a DLT4000 tape drive, a media loader, and a 5-cartridge
removable magazine.
The same SCSI target controller board controls the tape drive and the media loader. If
the controller detects the loader's presence when the system is turned on, the loader is
presented as a SCSI-2 medium changer device on LUN 1.
If the user issues the SCSI-2 medium changer commands to the DLT4500 mini-
library:
• Random access is enabled to the media stored in the magazine slots
• Sequential access is disabled to the media supported automatically in auto-loading
mode
If the user does not issue the SCSI-2 medium changer commands, the default mode of
operation is sequential access to the media supported automatically in auto-loading
mode.
Auto-loading is implemented as a side effect of the SCSI UNLOAD command, as
shown:
If …… Then ……
An unload is
specified
After winding the tape back into the cartridge and
moving the cartridge from the drive to the magazine
slot from which it came, the cartridge in the next slot
is moved from the magazine into the drive and made
ready.
The next slot is
empty, or the
cartridge unloaded
was for the last slot
in the magazine
No cartridge is loaded into the drive.