Table 5-109PERSISTENT RESERVATION IN Read Reservations Descriptor-Field Descriptions

Data

Description

Field

 

Reserva-

The Reservation key field contains an 8-byte value that identifies the reservation key under which the per-

tion Key

sistent reservation is held.

 

If the Scope field (Byte 13, bits 4 – 7) represents an “Extent” reservation, the Scope-Specific Address field

Scope-

contains the logical block address (LBA) of the first block of the extent and the Extent Length field (Bytes

14 – 15) contains the number of blocks in the extent.

Specific

If the Scope field represents an “Element” reservation, the Scope-Specific Address field contains the Ele-

Address

 

ment address, zero-filled in the most significant bytes to fit the field and the Extent Length field is set to

 

zero.

 

The value in this field indicates whether a persistent reservation applies to an entire logical unit, to a part

 

of the logical unit (defined as an extent), or to an element.

 

The values for the Scope field are:

 

Code Name Description

 

0h LU Logical Unit. Persistent reservation applies to the full logical unit. The LU scope is therefore imple-

 

mented by all device servers that implement PERSISTENT RESERVATION OUT.

 

1h Extent Persistent reservation applies to the specified extent. When Extent is the scope, it indicates that

Scope

the persistent reservation applies to the extent of the logical unit defined by the Scope-Specific Address and

Extent Length fields in the PERSISTENT RESERVATION OUT command’s parameter list. Note that an

 

 

extent is defined only for devices defining contiguous logical block addresses. The Extent scope is optional

 

for all device servers that implement PERSISTENT RESERVATION OUT.

 

2h Element Persistent reservation applies to the specified element. When Element is the scope, it indicates

 

that the persistent reservation applies to the element of the logical unit defined by the Scope-Specific Ad-

 

dress field in the PERSISTENT RESERVATION OUT parameter list. An element is as defined by the

 

SCSI-3 Medium Changer Commands (SMC) standard. The Element scope is optional for all device servers

 

that implement PERSISTENT RESERVATION OUT.

 

3h – Fh Reserved

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 5-56 for the applicable Type codes

 

and their meanings

 

Table 5-110presents the definitions of the characters of the available “Type” values

 

from the Type field of the PERSISTENT RESERVATION IN Read Reservations

 

parameters.

 

Each of the codes provides handling instructions for READ operations, for WRITE

 

operations, and for subsequent attempts to establish persistent reservations (referred to

 

as “Additional Reservations Allowed” in the table).

Maxtor Atlas 10K V

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