Quantum DLT 8000 Product Manual page 283

PERSISTENT RESERVATION IN Command (5Eh) (continued)
Table 5–63 PERSISTENT RESERVATION IN Read Reservations Descriptor — Field Descriptions
Data Field
Reservation Key
Scope-Specific
Address
Scope
Description
The Reservation key field contains an 8-byte value that identifies the reservation
key under which the persistent reservation is held.
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 Element 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
0h LU
1h Extent
2h Element
3h – Fh Reserved
Quantum DLT 8000 Tape System
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.
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.
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.
Reserved
SCSI Commands
(continued)
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