Datasheet

4.1 Control/Sense Commands
C141-C008 4-123
• Persistent reservations scope
The value in the "Scope" field shall indicate whether a persistent reservation
applies to an entire logical unit or to an element. The values in the "Scope" field
are defined in Table 4.86.
Table 4.86 Persistent reservations scope
Code Name Description
0h Logical Unit Persistent reservation applies to the full logical unit
1h Reserved Reserved
2h Element Persistent reservation applies to the specified element
3h-Fh Reserved Reserved
a) Logical unit scope
A "Scope" field value of LU shall indicate that the persistent reservation
applies to the entire logical unit. The Logical Unit scope shall be
implemented by all device servers that implement PERSISTENT RESERVE
OUT.
b) Element scope (not supported)
A "Scope" field value of Element shall indicate that the persistent reservation
applies to the element of the logical unit defined by the "Scope-specific
Address" field in the PERSISTENT RESERVE OUT parameter list. An
element is defined by the SCSI-3 Medium Changer Commands (SMC)
standard. The Element scope is optional for all device servers that implement
PERSISTENT RESERVE OUT.
• Persistent reservations type
The value in the "Type" field shall specify the characteristics of the persistent
reservation being established for all data blocks within the element or within the
logical unit. Table 4.87 defines the characteristics of the different type values. For
each persistent reservation type, table 4.87 lists code value and describes the
required device server support. In table 4.87, the description of required device
server support is divided into two paragraphs. The first paragraph defines the
required handling for read operations. The second paragraph defines the required
handling for write operations.