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Page 20
ERASE
Command Descriptor Block
Field Descriptions
The Erase command marks the tape, from the current position to the end of tape, as
erased.
Bits
Byte
7
6
0
1
Ignored LUN
2
3
4
5
Field
Bytes
Bits
Operation
0
Code
Ignored
1
5-7
Logical
Unit
Immed
1
1
Long
1
0
Reserved
Control
If the Immediate (Immed) flag is set to 1, then the drive validates the command and
waits for any previous command from any host to complete including any immediate
commands currently being processed and for any buffered data to be flushed to
tape. It will then report a deferred error for any preceding command or buffered data
if appropriate. If there is no deferred error, the drive reports good status and initiates
the command. If the Immediate (Immed) flag is set to 0, status is not returned until
after the command has completed.
If the Long bit is set, EOD is written at the current position. Data Set Separators are
then written from EOD to the end of the medium to overwrite any data currently on
the tape. If the Long bit is clear, then an EOD is written at the current position
marking it as end of data.
5
4
3
Operation Code (19h)
Reserved
Reserved
Reserved
Reserved
Control
Description
The Operation Code for Erase is 19h.
The LUN field is residual from the SCSI-1 days and is ignored.
0 = Status is not returned until the tape is erased.
1 = Status is returned as soon as the operation is initiated.
0 = Short Erase is performed and EOD is recorded at the current
tape position.
1 = Long data-security Erase is performed, and EOD is recorded
from the current tape position to the end of the tape.
All reserved bits must be 0.
See Control Byte Format on page 18.
LTO SCSI Interface Manual
2
1
0
Immed
Long
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