IBM System Storage Subsystem DS5020 - Manual (Page 89)

One DS5020 and one storage expansion enclosure
If you are cabling one DS5020 storage subsystem to one storage expansion
enclosure, Figure 37 shows the correct cabling topology.
Note: Figure 37 illustrates the drive channel connections between the DS5020 and
the storage expansion enclosures. Do not use Figure 37 as the cabling
diagram. Follow the instructions in “DS5020 storage subsystem and
supported storage expansion enclosure drive cabling schemes” on page 67
for specific cabling instructions.
DS5020
Port 2, drive channel 1
Port 1, drive channel 1
Port 1, drive channel 2
Port 2, drive channel 2
1A 1B
1A 1B
Figure 37. Cabling for one DS5020 and one storage expansion enclosure
Chapter 3. Cabling the storage subsystem 59