Maxtor 10K III Computer Drive User Manual


 
SCSI Description
5-126 Maxtor Atlas 10K III
The RELEASE and the RESERVE commands are used for contention resolution in
multiple-initiator systems. The RELEASE command is used to release a previously
reserved logical unit. The drive will not return an error if the initiator attempts to
release a reservation that is not currently valid. The data format and field descriptions
are shown in Table 5-161 and Table 5-162 respectively.
RELEASE (6) Command Descriptor Block-Data Format
RELEASE (6) Command -Field Descriptions
Assuming that the RELEASE Command Descriptor Block is valid, the drive
always returns a GOOD status for this command. An actual release only hap-
pens if the initiator has the unit reserved for itself or a third-party initiator.
0 Operation Code (17h)
1 Reserved 3rdPty Third Party Device ID Extent
2 Reservation Identification
3 - 4 Reserved
5 Control
3rdPty
Third Party Release allows an initiator to release a logical unit that was previously
reserved. If the value in this field is 0, third party release is not requested.
When the value is 1, the drive releases the specified logical unit, but only if the res-
ervation was made by the initiator using a third-party reservation that requested the
release for the same SCSI device as specified in the Third Party Device ID field.
Third Party De-
vice ID
Required if the 3rdPty bit is 1. This field specifies the SCSI ID (0 through 7 only) of
the initiator whose third party reservation is being released. (This field must be set
if the initiator of the original third party RESERVE is the source of the RELEASE.)
Extent The drive supports reservations only on entire logical units.
Reservation
Identification
Any value in this field is ignored by the drive.