User's Guide

Chapter 2 Media Changer Commands
Reserve Element (10) Command (56h)
Quantum SuperLoader 3 Software Interface Guide 131
Table 60 Reserve Element
(10) Command
If the
LongID bit = 1 and the Element bit = 0, then the parameter list length
is eight and the parameter list has the following format.
Field Description
3rd Pty When set to 1, it indicates that the
Third Party Device ID field is valid.
LongID When 0, indicates that the third party device associated with the
reservation release has a number smaller than 255 and the ID value can be
sent within the
CDB. If set = 1, indicates that the third party device ID is
greater than 255, the ID value within the
CDB is ignored, and the parameter
list length is at least eight.
Element Not supported. Must be 0.
Reservation
Identification
Ignored.
Third Party
Device ID
Required and used only when the
3rdPty bit is set, in which case this field
specifies the SCSI ID of the initiator to be granted the reservation of the
logical unit. The drive preserves the reservation until one of the following
occurs:
• It is superseded by another valid
RESERVE command from the initiator;
• It is released by the same initiator;
• It is released by a
TARGET RESET message from any initiator;
• It is released by a
TARGET RESET message from any initiator; or
• It is released by a hard reset condition.
The media changer ignores any attempt to release the reservation made by
any other initiator. For example, if
ID7 sends ID2 a Third Party reservation
on behalf of
ID6 (the target at ID2 gets reserved for the initiator ID6), then
only
ID7 can release the target at ID2 (using a Third Party release). ID6 cannot
release the reservation even though the reservation was made on its behalf.
Parameter List
Length
This field specifies the length, in bytes, of the parameter list that will be
transferred from the initiator.