Reference Guide

Chapter 4 SCSI Commands
PERSISTENT RESERVE IN Command (5Eh)
DLT-S4 Interface Reference Guide 213
Reservation Parameters —
Data Format
Table 116 Read Reservation
Parameters — Field
Descriptions
Bit
7 6 5 4 3 2 1 0
Byte
0 — 3
(MSB)
PRGeneration
(LSB)
4 — 7
(MSB)
Additional Length (n – 7)
(LSB)
8 — n
(MSB)
Reservation Descriptors
(LSB)
Field Description
PRGeneration Persistent Reservations Generation. The value in this field is a 32-bit counter in
the drive that is incremented each time a
PERSISTENT RESERVE OUT command
requests a Register, Clear, Preempt, Preempt & Abort, or Register & Move
operation. Note that
PERSISTENT RESERVE IN commands do not increment the
counter, nor do
PERSISTENT RESERVE OUT commands that perform a Reserve
or Release service action, or that are not performed due to an error or a
reservation conflict. The value in the Generation field is set to 0 as part of the
power-on self test process.
The value in the Generation field allows the application client that examines the
value to verify that another application client has not modified the configuration
of the initiators attached to a logical unit without notifying the application client
doing the examination.