Sun Microsystems StorEdge D2 Array Best Practices Manual page 27

numbers, used by the SAF-TE commands to communicate with the drive slots, are
0-5 for ESM 0 and 0-5 for ESM 1 (in the split-bus configuration SAF-TE commands
issued through an ESM communicate with only the six drives associated with that
ESM). Two hosts can be attached to ESM 0 and to ESM 1.
The split-bus configuration forms the basis for a high-availability storage
configuration with no single point of failure in a single Sun StorEdge D2 enclosure.
This high-availability configuration is created by using independent host adapters to
communicate with each ESM and mirroring data between the two independent
busses.
Slot Slot Slot Slot
0 1 2
SCSI SCSI SCSI SCSI
ID 0 ID 1 ID 2 ID 3
Sun StorEdge D2 Single ESM Front View (Single Bus)
FIGURE 2-3
ESM 0 Slots
Slot Slot Slot Slot
0 1 2
SCSI SCSI SCSI SCSI
ID 8 ID 9 ID 10 ID 11
Sun StorEdge D2 Dual ESM Front View (Split Bus)
FIGURE 2-4
Slot Slot
3 4 5
SCSI SCSI
ID 4 ID 5
Slot Slot
3 4 5
SCSI SCSI
ID 12 ID 13
Slot Slot Slot Slot
6 7 8 9
SCSI SCSI SCSI SCSI
ID 8 ID 9 ID 10 ID 11
ESM 1 Slots
Slot Slot Slot Slot
0 1 2 3
SCSI SCSI SCSI SCSI
ID 8 ID 9 ID 10 ID 11
Chapter 2 Hardware Installation and Configuration
Power On LED
Slot Slot
10 11
SCSI SCSI
ID 12 ID 13
Subsystem Fault LED
Power On
LED
Slot Slot
4 5
SCSI SCSI
ID 12 ID 13
Subsystem Fault LED
2-7