28 release (6) command (17h) – Maxtor 10K V User Manual

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Maxtor Atlas 10K V

5-109

5.28

RELEASE (6) Command (17h)

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 5-155 and Table 5-156 respectively.

Table 5-155

RELEASE (6) Command Descriptor Block-Data Format

Table 5-156

RELEASE (6) Command -Field Descriptions

Note:

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.

Bit

Byte

7

6

5

4

3

2

1

0

0

Operation Code (17h)

1

Reserved

3rdPty

Third Party Device ID

Extent

2

Reservation Identification

3 - 4

Reserved

5

Control

Field

Description

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 reservation 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 Device

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. The value must be 0.

Reservation

Identification

Any value in this field is ignored by the drive.

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