Reference Guide

Chapter 4 SCSI Commands
PERSISTENT RESERVE IN Command (5Eh)
DLT-S4 Interface Reference Guide 215
Table 117 PERSISTENT
RESERVE IN Read
Reservation Descriptor — Field
Descriptions
Table 118 describes the available Type values from the Type field of the
PERSISTENT RESERVE IN Read Reservation parameters. Each of the
codes provides handling instructions for
READ and WRITE operations and
for subsequent attempts to establish persistent reservations (referred to as
“Additional Reservations Allowed” in the table).
Table 118 PERSISTENT
RESERVATION IN Type Codes
Field Description
Reservation Key Contains an 8-byte value that identifies the reservation key under which the
persistent reservation is held.
Scope-Specific
Address
Always set to 0.
Scope The drive only supports reservations of the entire logical unit. Always set to 0.
Type Specifies the characteristics of the persistent reservation (see table 118
for the
applicable Type codes and their meanings).
Code Name Description
0h Obsolete ---
1h
WRITE
Exclusive
READS: Shared; any application client on any initiator can execute
commands that perform transfers from the drive to the host.
WRITES: Exclusive; any command from any initiator other than the initiator
that holds the persistent reservation that attempts a transfer to the drive
results in a reservation conflict.
ADDITIONAL RESERVATIONS: Allowed; any initiator may reserve the logical
unit, extents, or elements as long as the persistent reservations do not conflict
with any reservations already known to the drive.
2h Obsolete ---