Fujitsu MAS3735 Computer Drive User Manual


 
Command Specifications
3 - 50 C141-E167
The PERSISTENT RESERVE IN command obtains information about the reservation requirements
and reservation keys that are valid in the target range. This command is used in combination with
the PERSISTENT RESERVE OUT command (See Section 3.1.19).
When this command is received, if the reservation in the target is enabled by the RESERVE
command, the command is rejected and is returned with the RESERVATION CONFLICT status.
If the reservation is enabled by a persistent reservation, this command can be executed normally.
The length of the PERSISTENT RESERVE IN parameter data that can be returned by this command
is displayed in the parameter data field. If the specified allocation length in the CDB is not sufficient
for containing the entire parameter list, a portion of the parameter list from byte 0 to the specified
allocation length is sent. This is not assumed to be an error. If the remaining part of the parameter
must be read, the initiator must specify a value that is sufficient for containing the entire list in the
Allocation Length field and issue the PERSISTENT RESERVE IN command again.
3.1.18.1 PERSISTENT RESERVE IN service actions
In a service action, nonvolatile memory in the logical unit may be required to be in the ready state to
access information about reservation requirements or registration (MA*3*** series product requires
the drive to be ready). If the nonvolatile memory is not ready, the drive returns the CHECK
CONDITION status. The sense key is set to NOT READY [=2]. The sense data is specified with
the same value returned by the TEST UNIT READY command.
The service action codes for the PERSISTENT RESERVE IN command are listed below.
Code Name Description
00h READ KEYS Reads all of the registered reservation keys.
01h READ RESERVATIONS Reads all of the persistent reservations that are
currently enabled.
02h-1Fh Reserved
3.1.18.1.1 READ KEYS
In the READ KEYS service action, the drive transfers the following information to the initiator as a
parameter data list.
Current generation value (See Section 3.1.18.2)
All of the reservation keys that are currently registered (8 bytes each)
If several initiators register the same key, the key is listed once for each registration. Therefore, the
key is displayed on the list as many times as the number of initiators. (The keys are not listed in the
order of their registration but in ascending order based on INIT IDs. For example, INIT ID#0 is
listed first.) The keys are registered in the REGISTER service action by the PERSISTENT
RESERVE OUT command.