
42 Commands
ERASE 19h
The ERASE command is used to erase data on tape from the current logical
position. The Long bit is used to decide whether the ‘old’ data is physically
overwritten or not.
Pre-Execution Checks:
Command Descriptor Block:
CDB Fields:
Note The only use for short erase is to truncate data at current logical
position. It cannot be used to create a “hole” in the tape into
which data can subsequently be written “in place”. This will
merely cause the drive to streamfail. The logical tape position is
unaffected by this command. A
CHECK CONDITION for Early
Illegal Field Reservation Deferred Error Unit Attention
Media Access Media Write Diagnostic Status
7 6 5 4 3 2 1 0
0
Operation Code (19h)
1
Reserved (0) Immed Long
2
Reserved (0)
3
Reserved (0)
4
Reserved (0)
5
Control
Immed 0 The drive reports status after the command has completed.
1 The drive reports status when it starts the command (after any pre-
execution checks and prerequisite unloads have completed).
Long The Long bit controls the distance to be erased.
0 The current position becomes the end of logical data.
1 End of Data is written, followed by Data Set Separators to the end of the
tape.