Fujitsu MAS3367 Computer Drive User Manual


 
3.1 Control/Sense Commands
C141-E167 3 -
53
The "Additional Length" field contains a count of the number of bytes to follow in the "Reservation
Descriptors" field. If the specified allocation length in the CDB of the PERSISTENT RESERVE IN
command is not sufficient for containing the entire parameter list, a portion of the parameter list
from byte 0 to the specified allocation length is transferred to the initiator. If the remaining data of
the list may be truncated, valid reservation descriptors are created in the "Additional Length" field.
1. The format of the PERSISTENT RESERVE IN reservation descriptors is shown below.
Bit
Byte
76543210
0(8) (MSB)
Reservation Key
7 (15) (LSB)
8 (16) (MSB)
Scope-specific Address
11 (19) (LSB)
12 (20) X'00' (Reserved)
13 (21) Scope Type
14-15
(22-23)
X'00' (Reserved)
The reservation requirements kept by a logical unit are displayed with the Reservation Descriptors in
the parameter data. The Descriptors include reservation keys of the initiator that holds the
reservation requirements. The Descriptors also include the "Type" value and the "Scope" value of
the reservation requirements specified by the PERSISTENT RESERVE OUT command (See
Sections 3.1.18.3.1 and 3.1.18.3.2).
The reservation key indicates a key registered according to the reservation requirements. If each
initiator uses a unique key, the application must associate the initiator that holds the reservation
requirements with the reservation key.
If "Scope" is the Element reservation, the "Scope-specific Address" field indicates an element
address, where zeros are filled in the upper bytes. If the "Scope" is a logical unit reservation, the
"Scope-specific Address" field shall be set to zero.
Note: MA*3*** series product does not support the Element reservation.
3.1.18.3.1 Persistent reservation scope
The value in the "Scope" field indicates that either a persistent reservation applies to an entire logical
unit, or it applies part of the logical unit (element). "Scope" field values are defined below.