Maxtor 10K III Manual Do Utilizador

5-98

Maxtor Atlas 10K III

Table 5-120 provides detailed descriptions of each of the PERSISTENT 
RESERVATION OUT command’s seven possible service actions (Service Action 
codes appear in bits 0 – 4 of Byte 1).

Table 5-120   

Type

The value of the Type field specifies the characteristics of the persistent reservation 
being established for all data blocks within the extent or within the logical unit. Refer 
to Table 5-121 for the applicable Type codes and their meanings

Parameter 

List Length

Fields contained in the PERSISTENT RESERVATION OUT parameter list specify the res-
ervation keys and extent information required to perform a persistent reservation ser-
vice action.

The parameter list is 24 bytes in length; the Parameter List Length field contains 24 
(18h) bytes.

+,

9

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00h

Register

When the command executes a Register service action, it registers a reserva-
tion key with a device server without generating a reservation. The device serv-
er holds these reservation keys from each initiator that performs a PERSISTENT 
RESERVATION OUT command with a Register service action until the key is 
changed by a new PERSISTENT RESERVATION OUT command with Register 
service action from the same initiator, or until the initiator registration is re-
moved by:

• Powering down the logical unit, if the last 

Activate Persist Through Power Loss 
(APTPL; see Figure 5-55 and Table 5-61) 
received by the device server was 0;

• Performing a Clear service action;

• Performing a Pre-empt service action;

• Performing a Pre-empt and Clear service 

action; or

• Performing a Register service action from the 

same initiator with the value of the service 
action reservation key set to 0.

When a reservation key has not yet been established or when the reservation 
key has been removed, a reservation key of 0 is used when the initiator per-
forms a PERSISTENT RESERVATION OUT with the Register service action. 
When the reservation has been removed, no information is reported for the ini-
tiator in the Read Keys service action of the resulting PERSISTENT RESERVA-
TION IN command.

01h

Reserve

A PERSISTENT RESERVATION OUT command with Reserve service action cre-
ates a persistent reservation with a specified Scope and Type.
Persistent reservations are not superseded by a new persistent reservation from 
any initiator except by the execution of a PERSISTENT RESERVATION OUT 
command that specifies either a Pre-empt or Pre-empt and Clear service action. 
New persistent reservations that do not conflict with an existing persistent res-
ervation execute normally. Persistent reservations of logical units or extents 
having the same Type value are permitted if no conflicting persistent reserva-
tions are held by another initiator. When these types of overlapping reserva-
tions are released, each of the extent reservations and logical unit reservations 
are removed with a separate Release service action. Multiple identical reserva-
tions from the same initiator are all released simultaneously via a single Release 
service action that matches the reservations.

"&*2,

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