TAPE UNIT SCSI COMMANDS M2488 PRODUCT GUIDE
4-16 CG00000-011503 REV. A April 1997
A Long bit set to zero causes a 7.8 +/- 0.4 mm of the medium to be recorded with an erase tone
(special pattern along with a 2-mm IBG). This is known as the Erase Gap based on the Gap Size
field in the Device Configuration Mode Page. An End-of-Data (EOD) mark is written after this
type of erase operation. If the early warning condition is encountered while erasing with the long
bit set to zero a CHECK CONDITION status is sent by the target after completion of the erase
operation. The valid and EOM bits in the sense data are set to one. The information field will not
report any buffered erases.
A Long bit set to 1 indicates erasure of all remaining media on the logical unit (Data Security
Erase) by writing the tape with a random frequency two times that used for regular writes. Before
the Data Security Erase is performed, an Erase Gap is written. Following such a command, the
tape position is at end-of-partition (EOP).
** NOTE **
There is no limit to the number of sequential erase patterns that can
be written. However, if more than 680 mm of tape (68 +/- 2 erase pat-
terns +2.0 mm IBG) is read b y the controller, a BLANK C HECK is sig-
naled.
4-3.5.2 ERASE Sense Keys
One of the following sense keys may be returned if a CHECK CONDITION was indicated:
SENSE KEY CONDITION DESCRIPTION
1h RECOVERED ERROR 1. Recovery was performed when writing buffered data before the erase
occurred.
2. Retries were needed to complete the ERASE.
2h NOT READY Logical unit was not ready (tape was not loaded or was not ready).
3h MEDIUM ERROR 1. Write of buffered data failed due to defective tape.
2. End-of-Medium was encountered when performing an Erase Gap oper-
ation (Long bit =0).
3. An attempt was made to write 36-track data on 18-track formatted
medium.
4. The tape length in the cartridge is too long or too short.
4h HARDWARE ERROR 1. Write of buffered data failed due to a hardware error.
2. ERASE command failed due to unrecoverable errors on the SCSI inter-
face.
5h ILLEGAL REQUEST Reserved bit was set in the CDB of the ERASE command.
6h UNIT ATTENTION Indicates the ERASE command was not performed due to one of the fol-
lowing:
1. The tape cartridge was changed.
2. The target was reset.
3. The Mode parameters were changed by another initiator.
4. The version of the microcode was changed (microcode downloaded).
5. A cartridge was loaded with a tape length that is too long or too short.