Maxtor 10K V Benutzerhandbuch

Maxtor Atlas 10K V

5-81

The PERSISTENT RESERVATION OUT command is a 10-byte command used 
to reserve a logical unit or an extent within a logical unit for the exclusive or shared 
use by an initiator. The command is used in conjunction with the PERSISTENT 
RESERVATION IN command; it is not used with the RESERVE and RELEASE 
commands.

Persistent reservations conflict with reservations made via the RESERVE command. 
Initiators that perform PERSISTENT RESERVATION OUT actions are identified 
by a reservation key assigned by the application client. The client may use the 
PERSISTENT RESERVATION IN command to identify which other initiators 
within a system hold conflicting or invalid persistent reservations and use the 
PERSISTENT RESERVATION OUT command to preempt those reservations if 
necessary.

Note that since persistent reservations are not reset by the TARGET RESET task 
management function or other global actions, they can be used to enact device sharing 
among multiple initiators. The PERSISTENT RESERVATION OUT and 
PERSISTENT RESERVATION IN commands provide the means for resolving 
contentions in multiple-initiator systems with multiple port target. By using the 
reservation key to identify persistent reservations, it is possible to determine which 
ports hold conflicting persistent reservations and to take over such reservations from 
failing or “greedy” initiators.

illustrates the format of the PERSISTENT RESERVATION OUT command. Table 
5-113 explains the data fields of the command.

Table 5-112   

0

Operation Code (5Fh)

1

Reserved

Service Action

2

Scope

Type

3 - 6

Reserved

7 – 8

(MSB)

Parameter List Length (18h)

(LSB)

9

Control