Quantum 10K II User Manual

Page 185

SCSI Description

5–118

Quantum Atlas 10K II Ultra160/m SCSI Hard Disk Drives

PERSISTENT RESERVATION IN Command (5Eh) (continued)

Table 5–55 PERSISTENT RESERVATION IN Read Reservations Descriptor — Field

Descriptions (continued)

Data Field

Description

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

Logical Unit. Persistent reservation applies to the
full logical unit. The LU scope is therefore
implemented by all device servers that
implement PERSISTENT RESERVATION OUT.

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.

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 Address 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

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