Sony DDS-4, Руководство по описанию продукции

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6 - 49 SONY SDT-10000/SDT-11000 DDS Tape Drive
6. COMMAND SPECIFICATION
The Host may, therefore, partition a tape into one partition which spans the whole physical length of the tape or into two
partitions, each of which will behave as completely separate and independent tapes.
A tape does not require partitioning prior to use. If a Host only wishes to use a single partition tape, then there is no need
to send this page. On the first WRITE to a blank tape, the device will create the System, Reference and Vendor areas on
tape before proceeding with the write. To reformat 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:
The 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.
Medium Format Recognition:
This field is only valid on a MODE SENSE and is set to 03h to indicate that the drive is capable of format and
partition recognition.
Partition Sizes:
This field allows the initiator to allocate the capacity of the second partition, Partition 1. It will also allow the
initiator to reallocate the capacity of previously partitioned tapes.
The Partition Size specifies the capacity of Partition 1 in Megabytes. The drive rounds the Partition Size to the next
whole group value and then applies an algorithm which allows for the writing of ECC-3 frames and for RAW error
recovery so as to reserve sufficient physical space on the media for the specified capacity.
If the Additional Partitions Defined and Partition Size fields are set to zero the drive will initialize the tape as Partition
0, spanning the whole length of the tape.
Partition 0 size is only valid during MODE SENSE and is ignored during MODE SELECT Remaining Capacity goes to
P.0.
MODE SELECT