7-4
Ultra320 SCSI Storage Enclosures
Ultra320 SCSI Split-bus Configurations
Note:
The Ultra320 Storage Enclosure does not support daisy-
chaining JBOD shelves.
A split-bus configuration has two separate busses with up to six
disk drives on each bus. In this configuration, the enclosure has an
I/O module in one I/O slot, and an I/O blank in the other.
The busses can connect to the same host or to two different hosts.
Note:
The I/O blank must be installed to maintain adequate
airflow and cooling in the enclosure.
If you are not populating all drive slots on the enclosure, you
must install carrier blanks in the empty slots to maintain
adequate airflow and cooling.
Split-bus SCSI IDs
The Ultra320 SCSI Storage Enclosure’s SCSI IDs are hard set and
cannot be changed.
In a split-bus enclosure, each bus has seven SCSI IDs. SCSI ID 6 on
each bus is reserved for the host. The I/O module has SCSI ID 15.
shows the SCSI ID assignments for a split bus:
Note:
SCSI IDs 6 and 7 are not used; they are reserved for host
connections. SCSI ID 15 is assigned to the I/O module.
Table 7-1 SCSI ID Assignments for a Split Bus
Slot 12
ID 0 (Bus 2)
Slot 9
ID 3 (Bus 2)
Slot 6
ID 0 (Bus 1)
Slot 3
ID 3 (Bus 1)
Slot 11
ID 1 (Bus 2)
Slot 8
ID 4 (Bus 2)
Slot 5
ID 1 (Bus 1)
Slot 2
ID 4 (Bus 1)
Slot 10
ID 2 (Bus 2)
Slot 7
ID 5 (Bus 2)
Slot 4
ID 2 (Bus 2)
Slot 1
ID 5 (Bus 1)