Tandberg Data
About Tape Streamers
2-6
Tandberg SLR Product Line SCSI Functional Specifications
2.3.2.
Selecting a Partition
Two commands makes it possible to select a partition for
read or write operations; the LOCATE command and the
MODE SELECT command.
2.3.2.1.
Selecting a Partition Using LOCATE
The LOCATE command can be used to specify the active
partition. The Change Partition (CP) must be set to one
and the Partition field must be set to the desired
partition. The addressed partition must exist on the
volume mounted. The Drive will then move to the
specified partition before the actual block locate
operation starts.
The READ POSITION and MODE SENSE commands may be used to
read the current partition number in use.
When the partition has been changed, the Drive will stay
in the selected partition for all media access commands
until one of the following actions are taken (by the
Initiator):
A new LOCATE with CP set to one is executed.
A MODE SELECT command is executed that changes the
state of the Active Partition field in the Device
Configuration Parameters Page (page code 10h).
A LOAD command is executed. This command always
brings the tape to the beginning of the default
partition (partition 0).
The cartridge is removed from the Drive. A newly
inserted cartridge must be loaded before it can be
accessed. The load operation positions the tape at
the beginning of the default partition (partition 0).
This will be true whether the load operation happens
as a result of an Auto Load or an explicit LOAD
command (with the Load bit set to one).
2.3.2.2.
Selecting a Partition Using MODE SELECT
The MODE SELECT command can be used to specify the
active partition. The Device Configuration Parameters
Page (page code 10h) is used for this purpose. The
Change Active Partition (CAP) bit must be set to one and
the Active Partition field must be set to the desired
partition. The addressed partition must exist on the
volume mounted. The Drive will then position the tape at
the beginning of the specified partition.
The READ POSITION and MODE SENSE commands may be used to
read the current partition number in use.
When the partition has been changed, the Drive will stay
in the selected partition for all media access commands
until one of the following actions are taken (by the
Initiator):
A new MODE SELECT command is executed that changes
the state of the Active Partition field.
