Water Dispenser User Manual

C141-E124-01EN 3 - 63
3.1.18.3.1 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 below.
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
3.1.18.3.1.1 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.
3.1.18.3.1.2 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.
3.1.18.3.2 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 3.2 defines the
characteristics of the different type values. For each persistent reservation type, table 3.2 lists code
value and describes the required device server support. In table 3.2, 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.