Sony SDX-700C, Product Specifications Manual

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4.Operation
4-6 SONY AIT-3 drive SDX-700 series Ver.2.1
4.5.1.
Tape Partitions
Tapes can be formatted as a single data space or as two partitions. With two partitions, each has the same structure
and can be written independently. Some for example, the partition further from BOM (Partition 0) can contain data
files, and the partition closer to BOM (Partition 1) could contain a directory of these files, written later.
With the exception of the Device area on the tape, each partition of a 2-partition tape is identical to a single data
space tape in structure. This means each partition has its own Tape Log area; this is necessary because the
patterns of usage may be very different for each partition. Similarly, each has its own Vendor Group, because the
partitions might be written by different drives.
4.5.1.1.
Formatting Partitions
The SCSI MODE SELECT command is used to create partitions on a tape. The command can perform the following
operations:
- Set up two partitions on a blank tape.
- Convert a single data space tape to a 2-partition tape.
- Convert a 2-partition tape to a single data space tape.
- Change the size of both partitions on a 2-partition tape.
- Re-size the partitions of a 2-partition.
Note: Formatting is not needed for single partition operation.
The MODE SELECT, Medium Partitions Parameters Page (11h) is used to Format the tape. MODE SELECT,
Device Configuration Page (10h) is used to change from one partition to another, see the MODE SELECT
Command description in the SCSI command clause of this manual. The LOCATE Command also has the capability
to select a partition prior to positioning.
Any data on the tape before the format pass becomes inaccessible, even if the format pass is intended only to
change the size of the two partitions. The Tape Logs are also destroyed and new logs created.
If you do not format a new tape, it will be organized as a single data space tape. After data has been written to it,
whether it was first initialized or not, a format pass is necessary to alter its characteristics and hence how it is handled
by the tape drive system.
Note: The format operation can be very time consuming depending on the requested size of the first partition on the
tape. The amount of time required can be approximated by use of the following formula:
- Number of Megabytes in Partition 1
×
0.006 = number of minutes required
- Add 30 additional seconds for processing overhead
4.6.
Maintenance, Troubleshooting and Service
4.6.1.
Head Cleaning
The SDX-700C has a built in head cleaning function that helps prevent/recover from head contamination problems
which eliminates the need for periodic head cleaning with a head cleaning cassette as required with other tape
formats. However, severe cases of contamination from which the drive can not recover may require use of a cleaning
cassette.
4.6.1.1. Message when cleaning cassette is necessary
(1) When drive displays cleaning cassette requirement, (Cleaning Request LED is on or in case of SCSI, CLN bit
is set at Request Sense.) use specified cleaning cassette (model name : SDX-TCL )
(2) The message for cleaning cassette requirement does not appear periodically.
4.6.1.2.
Usage of cleaning cassette
(1)
Drive displays cleaning cassette requirement.
(2)
When specified cleaning cassette is inserted, automatic cleaning operation starts and when its over, the
cassette is ejected.