Quantum 10K II - Manual (Page 181)

SCSI Description
5–114 Quantum Atlas 10K II Ultra160/m SCSI Hard Disk Drives
PERSISTENT RESERVATION IN Command (5Eh) (continued)
Table 5–52 PERSISTENT RESERVATION IN Command — Field Descriptions
Data Field Description
Service Action Service actions that require information about persistent reservation and
registrations may require enabling of nonvolatile memory within the logical
unit.
Service action codes available are:
Code
Name Description
00h Read Keys Reads all registered Reservation keys
01h Read Reservations Reads all current persistent reservations
02 – 1Fh Reserved Reserved
A “Read Keys” service action requests that the device server return a
parameter list that includes a header and a complete list of all of the
reservation keys currently registered with the device server. If multiple
initiators have registered with the same key, then the key is listed multiple
times, once for each registration. Refer to Figure 5-51 and Table 5-53 for
information about Read Keys parameter data.
A “Read Reservation” service action requests that the device server return a
parameter list that contains a header and a complete list of all persistent
reservations that are presently active in the device server and its extents.
Note that duplicate persistent reservations from the same initiator are not
reported. Refer to Figure 5-53 and Table 5-54 for information about Read
Reservations parameter data.
Allocation
Length This field indicates how much space has been reserved for the returned
parameter list (Read Keys or Read Reservations parameters). The actual
length of the parameter data is indicated in the parameter data field for
those parameters.
If the Allocation Length is not sufficient to contain the entire list of
parameters, the first portion of the list that does fit is returned. If it is
determined that the remainder of the list is required, the client should send
a new PERSISTENT RESERVATION IN command with an Allocation Length
field large enough to contain the entire list of parameters.