TAPE UNIT SCSI COMMANDS M2488 PRODUCT GUIDE
4-114 CG00000-011503 REV. A April 1997
Superseding reservations. An initiator that currently has a logical unit reserved may modify the
current reservation by issuing another RESERVE UNIT command to the same logical unit. The
superseding reservation releases the current reservation if the superseding reservation request is
granted. The current reservation is not modified if the superseding reservation request cannot be
granted. If the superseding reservation cannot be granted because of conflicts with a previous res-
ervation (other than the current reservation), then the target returns RESERVATION CONFLICT
status.
4-3.25.3 RESERVE UNIT Sense Keys
One of the following sense keys may be returned if a CHECK CONDITION was indicated:
SENSE KEY CONDITION DESCRIPTION
1h RECOVERED ERROR Recovery was performed while writing buffered data before the
RESERVE UNIT occurred.
3h MEDIUM ERROR 1. Write of buffered data failed due to a defective tape.
2. An attempt was made to write 36-track data on 18-track formatted
medium.
4h HARDWARE ERROR Write of buffered data failed due to a hardware failure.
5h ILLEGAL REQUEST 1. Reserved bit was found set in the CDB of the RESERVE UNIT
command.
2. Initiator attempted to perform a third-party reservation for its own
ID.
3. The Flag bit was set but the Link bit was not set.
6h UNIT ATTENTION Indicates the RESERVE UNIT command was not performed due to
one of the following:
1. The tape cartridge may have been changed.
2. The target has been reset.
3. The Mode parameters have been changed by another initiator.
4. The version of the microcode has been changed (microcode down-
loaded).
5. A cartridge was loaded with a tape length that is too long or too
short.
Bh ABORTED COMMAND The RESERVE UNIT command was aborted.
Dh VOLUME OVERFLOW Write of buffered data prior to the RESERVE UNIT operation failed
because physical End-of-Tape has been reached.