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Page 78
Variable Mode Residual Data
Completion Status
When the Fixed bit is reset (0), the residual data is always set to the CDB Transfer
Length.
For example, assume the following:
•
The drive is currently positioned before block N.
•
Block N + 1 contains 512 bytes.
The host issues a READ command with a CDB Transfer Length of 514, indicating
514 bytes of data to be read. The drive transfers the first 512 bytes of block N; then
stops because of an Incorrect Length error. The logical position after the error is after
byte 512 of block N.
If the SILI bit is set (1), the drive does not report a Check Condition (caused by
Incorrect Length error).
If the SILI bit is reset (0), the drive reports a Check Condition, and the residual is set
to 2 (CDB Transfer Length = 514).
In the above example, if the block size of block N is 514 bytes and a READ
command specifies a Transfer Length of 512 bytes, the drive transfers the first 512
bytes of block N; then skips the last two bytes to position itself at the end of byte 514
of block N. The residual is set to -2. Because the actual block length exceeds the
CDB Transfer Length, the drive unconditionally reports Check Condition. In this case,
the residual is set to -2.
Code
Message
Description
• The drive is ready to perform any appropriate command.
00h
Good
Status
• The drive remains in any previously set mode.
• The tape is positioned on the EOT side of the last block read.
02h
Check
Use the Request Sense command to retrieve status information. Possible
Condition
Sense Keys are:
Code
02h
03h
04h
05h
06h
08h
Message
Description
Not Ready
No cartridge is in the drive.
Media Error
Unrecoverable data error encountered.
Hardware Error
Parity error on the SCSI bus or drive hardware
failure.
Illegal Request
The Command Descriptor Block is invalid.
Unit Attention
The cartridge was changed, or the drive was re-
set prior to this command.
Blank Check
The drive encountered EOD.
LTO SCSI Interface Manual
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