HP Q153090901 - Manual (Page 136)

Commands 136
Release Unit specific status:
Status is returned as follows:
• If the drive is not reserved, GOOD status is reported.
• If the drive is reserved by another host, GOOD status is reported.
• If the drive is reserved by this host for this host, the reservation status is cleared.
LongID This is always zero because device IDs greater than 255 are not supported.
Third-Party Device ID This is required and used only when the 3rd Pty bit is set. The device will
perform the release operation only if the initiator ID, the 3rd Pty bit and the
Third-Party Device ID are identical to those in the RESERVE UNIT command
that established the reservation.
The drive ignores any attempt to release the reservation made by any other
initiator, including the initiator for which the reservation was made.
If an initiator reserved the drive using a third-party reservation over itself, a
non-third-party RELEASE UNIT command could also release the reservation.