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Maxtor Atlas 10K V 5-77
Table 5-109 PERSISTENT RESERVATION IN Read Reservations Descriptor-Field Descriptions
Table 5-110 presents 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).
Data
Field
Description
Reserva-
tion Key
The Reservation key field contains an 8-byte value that identifies the reservation key under which the per-
sistent reservation is held.
Scope-
Specific
Address
If the Scope field (Byte 13, bits 4 – 7) represents an “Extent” reservation, the Scope-Specific Address field
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.
If the Scope field represents an “Element” reservation, the Scope-Specific Address field contains the Ele-
ment address, zero-filled in the most significant bytes to fit the field and the Extent Length field is set to
zero.
Scope
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
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