IBM TOTALSTORAGE DS4500 - Manual (Page 12)

If you want to connect more storage expansion enclosures into drive loops A and B, continue with
Step 3; otherwise, go to “Connecting a redundant drive loop to the DS4500” on page 13.
3. Connect additional storage expansion enclosures to drive loops A and B, as shown in Figure 12.
Starting with the second storage expansion enclosure, connect each additional storage expansion
enclosure into drive loops A and B in the same manner. Leave the In port on the last storage
expansion enclosure in the loop and the Out port on the first storage expansion enclosure unoccupied.
If you want to connect a second storage expansion enclosure group, repeat Step 1 on page 10 through
Step 3. Otherwise, go to “Connecting a redundant drive loop to the DS4500” on page 13. Figure 13 on
page 13 shows a second redundant storage expansion enclosure group (loop C and loop D on storage
expansion enclosure group 2).
ESM board
Loop B
Fibre Channel
cable
In Out
Figure 11. Connecting two storage expansion enclosures into redundant drive loop B
Loop B Loop A
Storage expansion
enclosure group 1
In In Out Out
Storage server
Figure 12. Connecting additional storage expansion enclosures to drive loops A and B
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