Hp Tru64 Unix; Openvms - HP StorageWorks DLT80 Reference Manual

HP Tru64 UNIX

The HP Tru64 UNIX operating system uses Dynamic Device Recognition (DDR)
which allows the operating system to recognize the DLT tape drive.
If the Tru64 UNIX system does not have a DDR entry to identify the DLT tape
drive, the system defaults to a generic SCSI device and to the default settings of
the tape drive.

OpenVMS

The OpenVMS operating system uses native SCSI recognition for locally attached
SCSI drives, which allows the operating system to recognize the DLT drive.
Recognition of the DLT drive allows non-default settings, such as the density
setting, to be used.
The DLT drive provides compression (called compaction in OpenVMS
terminology) so that the storage capability for tapes can be effectively doubled
when the DLT drive has been instructed to turn on compaction. This is known as
hardware compaction and should be used instead of the software compaction that
is sometimes provided by software products. The DLT drive is instructed by the
user to turn on hardware compaction through use of the OpenVMS INITIALIZE
and MOUNT commands. (See these two commands using Open VMS help from
the $ prompt).
The format for the INITIALIZE command is:
The INITIALIZE command controls whether data records are automatically
compacted and blocked together on any device that supports data compaction.
Data compaction and record blocking increase the amount of data that can be
stored on a single tape cartridge.
Note:
cartridge, that same status applies to the entire cartridge.
DLT80 Tape Drive Reference Guide
INITIALIZE
/MEDIA_FORMAT
/MEDIA_FORMAT=[NO]COMPACTION
Once data compaction or non-compaction has been selected for a given
Installing Software Drivers
39