2-20
Chapter 2: Hardware installation
Switched fabric connection in dual controller
In this type of connection, the channel link bypass is provided by external FC switches. Each application
server shown in the illustration below is equipped with two HBAs with FC links, connecting via two FC
switches to the SFP ports on individual controllers.
1 2 3 4 5 6
7 8 9 10 111 2
A
B
1 2x
6 x
8 x
2 x
9x
3x
1 0 x
4x
1 1x
5 x
7 x
1 x
E
th
ern
e
t
A
1 2 x
6x
8x
2x
9 x
3 x
10 x
4 x
11 x
5x
7x
1x
C
1 2 3 4 5 6
7 8 9 10 111 2
A
B
1 2x
6 x
8 x
2 x
9x
3x
1 0 x
4x
1 1x
5 x
7 x
1 x
E
th
ern
e
t
A
1 2 x
6x
8x
2x
9 x
3 x
10 x
4 x
11 x
5x
7x
1x
C
HBA 1
HBA 0
HBA 1
HBA 0
Eo n Pa th
HBA 1
HBA 0
HBA 1
HBA 0
CH0 A11 2
CH2 A11 6
CH0 B11 4
CH2 B11 8
CH0 B11 3
CH2 B11 7
CH0 A11 5
CH2 A11 9
CH1 A11 2
CH3 A11 6
CH1 B11 4
CH3 B11 8
CH1 B11 3
CH3 B11 7
CH1 A11 5
CH3 A11 9
CH0 A11 2
CH1 A11 2
CH0 B11 3
CH1 B11 3
CH0 B11 4
CH1 B11 4
CH0 A11 5
CH1 A11 5
CH2 A11 6
CH3 A11 6
CH2 B11 7
CH3 B11 7
CH2 B11 8
CH3 B11 8
CH2 A11 9
CH3 A11 9
L D
L D
R A ID
JB OD
L D
L D
A LV
B LV
B LV
A LV
Channels
Controller A
Controller B
Host
CH0, CH1, CH2, CH3
CH0, CH1, CH2, CH3
Configuration information
Number of controllers
2
Host servers
4 (or more via FC switches)
FC switches
2 (or 1 into 2 zones
Data path connection
Fault-tolerant data paths
Each logical partition is redundantly mapped to multiple host channel IDs in an AAPP (Active-Passive-
Passive-Passive) configuration. Logical volumes are managed by either controller A or controller B. The
passive IDs will only become functional when a single controller fails in the system.
The MPIO driver is needed on the application servers. This driver communicates with the system
firmware and performs load balance and automated distribution of I/Os across the preferred paths
(active IDs on data paths). TPGS (Target Port Group Service) is supported so that the I/Os are routed to
the preferred paths.
You can refer to the ID tags on the host links to see the related logical volume mapping and cable links
routing paths. The connection above can withstand failure of a single component such as controller,
HBA card, cable, or FC switch.
