4.Operation
SONY AIT-2 Turbo drive SDX-550V series Ver.1.0
4-5
Table 4-2: Normal LED indications
LED
Tape Motion
Cleaning Request
Replace Tape
Off
No Tape
Cleaning is Not Necessary No Media Error Occurred
On
Tape Loaded
Cleaning Request
Media Error Occurred
Flash Slowly
Tape Access in Progress
(Write/Read)
Cleaning is Not Completed
Flash Fast
Tape Access in Progress
(Others)
All LED Flash Fast
H/w Error Occurred
4.4.
Tape Format
The SDX-550V is an implementation of the Advanced Intelligent Tape (AIT-E Turbo, AIT-1, AIT-1 Turbo, AIT-2 and
AIT-2 Turbo) format, a standard developed by Sony for 8mm data storage drives.
- C1,C2, first and second level Error Correction Code, providing correction for random and Burst Symbol errors.
- C3 ECC, third level Error Correction Code, providing correction across frames within groups
- Read-After-Write, where data is verified immediately after it is written and re-written if there is any error.
- Repeat Writing, where every group is repeated a set number of times.
- Randomizer, to reduce inter-symbol interference.
4.4.1.
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.
4.4.1.1.
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