Quantum Scalar 218FC User Manual page 88

FCP LUN Value
0
1
2
3
4
5
6
(...)
13
14
15
16
17
(...)
Auto-Assigned Addressing Option
The Auto-assigned option is similar to Indexed Addressing, except that the table used is created through
SCSI device discovery on power up or reset, and not otherwise retained. As the unit performs device
discovery on the SCSI bus, the Index table relating FCP LUN values is filled with adjacent FCP LUNs
referencing each subsequent SCSI device. The host system will then detect every attached device without
voids, providing full device discovery to the host. This allows easy configuration in environments where
device ordering is not important, and hot plugging of SCSI devices will not occur. Tape libraries are
excellent candidates for using Auto-assigned Addressing. Configuration allows for discovery to be performed
in order of bus, target, or LUN as desired for the specific environment.
SCSI Initiators to Fibre Channel Targets
SCSI Initiators addressing Fibre Channel targets require that the BUS:TARGET:LUN selected be associated
with a given Fibre Channel destination ID and FCP LUN field. When a command is received on the SCSI
bus, the routing table for that unit is accessed to determine the destination ID, and thus, the FCP target device
to which the command is routed. When the FCP_CMD is issued, the LUN field associated with that entry is
used, to provide the additional LUN addressing behind the FCP target. Further identification in the later
phases of the command processing is by the exchange identifier. The table used is shown in Table 6. The
table can be manually edited, for both the Loop ID (AL_PA) and LUN field. Two bytes are provided for the
78 FC to SCSI Mapping
SCSI BUS:TARGET:LUN
0:0:0
0:1:0
0:2:0
0:3:0
0:4:0
0:5:0
(0:6:0 occupied by Initiator ID)
0:7:0
(...)
0:14:0
0:15:0
1:0:0
1:1:0
1:2:0
(...)
Indexed Addressing Table