IBM DS4800 - Fibre channel host loop configurations

One DS4800 and two storage expansion enclosures
If you are cabling one DS4800 Storage Subsystem to two storage expansion
enclosures, Figure 49 shows the recommended cabling schemes.
As Figure 49 and Figure 50 on page 72 show, when you connect additional storage
expansion enclosures, you can connect them either by using the additional port of
the drive channel or by continuing the connection from the existing redundant drive
channel pair. View 1 is the recommended cabling topology; View 2 is a possible
cabling topology, however, it is not recommended.
4
2
1
3
4
2
1 3
Drive Channel 1
Drive Channel 3
DS4800 Storage
Subsystem
DS4000 Storage
Expansion Enclosure
Controller A
Controller B
Right ESM (B)
Left ESM (A)
ds48052
4
3
2
1
4
3
2
1
Figure 48. One DS4800 and one storage expansion enclosure — Recommended cabling
Figure 49. View 1: One DS4800 and two storage expansion enclosures cabling —
Recommended
Chapter 3. Cabling the storage subsystem 71