Quantum DLT 8000 Product Manual page 281

PERSISTENT RESERVATION IN Command (5Eh) (continued)
The figure and table below illustrate and describe the data fields of Read Reservations
data parameters.
Bit 7
Byte
(MSB)
0 - 3
(MSB)
4 - 7
(MSB)
8 - n
Figure 5–66 Read Reservations Parameters — Data Format
Table 5–62 Read Reservations Parameters — Field Descriptions
Data Field Description
Generation The value in this field is a 32-bit counter in the device server that is incremented
each time a PERSISTENT RESERVATION OUT command requests a Register,
Clear, Pre-empt, or Pre-empt and Clear operation. Note that PERSISTENT
RESERVATION IN commands do not increment the counter, nor do PERSISTENT
RESERVATION OUT commands that perform a Reserve or Release service action,
or by a PERSISTENT RESERVATION OUT command that is not done due to an
error or a reservation conflict. The value in the Generation field is set to 0 as part
of the power on or reset processes.
The value in the Generation field allows the application client that examines the
value to verify that the configuration of the initiators attached to a logical unit
has not been modified by another application client without any notification of
the application client doing the examination.
Additional This field contains the count of the number of bytes of Reservation descriptors
Length (bytes 8 – n). Note that this field contains the number of bytes regardless of the
value prescribed by the Allocation Length field in the command's CDB.
Reservations One Reservation descriptor is reported for each unique persistent reservation on
Descriptors the logical unit when the PERSISTENT RESERVATION IN command has indicated
a Read Reservations action. Figure 5-67 and Table 5-63 detail the contents of
each Reservation Descriptors field.
6 5
Additional Length (n – 7)
Reservation Descriptors
(See Figure 5-67 / Table 5-63 for detail of a Descriptor Field)
Quantum DLT 8000 Tape System
4 3
Generation
SCSI Commands
2 1
(LSB)
0
(LSB)
(LSB)
5-137