Filter
Top Products
Command Specifications
3 - 56 C141-E167
3.1.19 PERSISTENT RESERVE OUT (5E)
Bit
Byte
76543210
0X'5E'
1 0 0 0 Service Action
2 Scope Type
300000000
400000000
500000000
600000000
7(MSB)
Parameter List Length (18h)
8 (LSB)
9 Control
The PERSISTENT RESERVE OUT command reserves a logical unit for exclusive or shared use by
a particular initiator. This command is used in combination with the PERSISTENT RESERVE IN
command. However, this command is not associated with the RESERVE or RELEASE command.
The persistent reservation conflicts with the reservation requirements specified by the RESERVE
command (RESERVATION CONFLICT). The initiator defines the reservation key. The
reservation key identifies the initiator that executes a service action of the PERSISTENT RESERVE
OUT command. The initiator can verify which initiators have caused conflicts with the reservation
requirements and which initiators hold invalid reservation requirements. If necessary, the initiator
can also preempt reservation rights by issuing the PERSISTENT RESERVE OUT command.
The set reservation requirements are not reset by processing such as the TARGET RESET task.
Therefore, a persistent reservation can be used for sharing a device among multiple initiators. The
PERSISTENT RESERVATION OUT and PERSISTENT RESERVATION IN commands provides
basic features for analyzing the dynamically changeable reservation status on a multi-initiator system
using multi-port targets. These commands can identify whether a particular reservation requirement
is held. They can also eliminate the requirements from an initiator that has an error or is not
cooperative.
When a drive receives this command and a reservation requirement has been held by the
RESERVE/RESERVE EXTEND command, the command is rejected and returned with the
RESERVATION CONFLICT status.
When this command is issued, if an invalid drive resource exists, the drive returns the "CHECK
CONDITION" status. The sense key is set to ILLEGAL REQUEST [=5]. Sense data is set to
INSUFFICIENT REGISTRATION RESOURCES [=55-04].
(However, SCSI devices do not report sense information.)