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6.Command Specification
FDP: The Fixed Data Partitions bit is not supported by the drive and if set, a CHECK CONDITION status is returned
with an ILLEGAL REQUEST Sense Key set.
SDP: The Select Data Partitions bit is not supported by the drive and if set, a CHECK CONDITION status is returned
with an ILLEGAL REQUEST Sense Key set.
IDP: The Initiator Defined Partitions bit is supported and, when set to one, indicates that the tape shall be partitioned
based on the Additional Partitions Defined field, PSUM and Partition Size field.
The SDX-550V operating in the AIT Format Mode allows tapes to be split into separate and independent partitions,
each with its own Reference, System and Vendor Group areas. The maximum size of a partition may be the entire
tape. A tape partitioned into several partitions may be considered a collection of several separate logical tapes. This
is illustrated below:
BOM
BOT
Partition 0
User
Device
System
EOD
Data
Area
Area
Area
BOM
BOT
Partition 0
User
Device
System
EOD DEV
Data
Area
Area
Area
BOM
BOT
Partition 0
User
Device
System
EOD
Data
Area
Area
Area
A tape does not require partitioning prior to use. On the first WRITE to a blank tape, the device creates the System,
Reference and Vendor areas before proceeding with the write. In order to reformat media from a two to a single, or
from a single to a two partition tape, the Host is required to use the Medium Partitions Parameter page.
PSUM: Partition Size Unit of Measured field defines the units in which the Partition Size value selects the partition
size, which in the case of this drive is Megabytes. Therefore, the drive returns 10b for a MODE SENSE and will only
accept this value for a MODE SELECT, otherwise a CHECK CONDITION status is returned with an ILLEGAL
REQUEST Sense Key set.
6-48
Single Partitioned Tape
Two Partitioned Tape
Partition 1
User
System
EOD
Data
Area
Area
Three Partitioned Tape
Partition 1
User
DEV
System
EOD DEV
Data
Area
Area
BOM=Beginning-of-Media (Physical)
BOT=Beginning-of-Tape (Logical)
EOM=End-of-Media (Physical)
EOP=End-of-Partition (Logical)
EOT=End-of-Tape (Logical)
Figure 6-2: Tape Partition Layout
Partition 2
User
System
EOD
Data
Area
Area
SONY AIT-2 Turbo drive SDX-550V series Ver.1.0
MODE SELECT
EOP/
EOM
EOT
EOP/
EOM
EOT
EOP/
EOM
EOT
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