Chapter 3. Planning 55
/SM590000Balanced host load across HBA ports
If the host has more than one HBA port per fabric, zone each host port with a separate 
group of Storwize V7000 ports. 
/SM590000Balanced host load across Storwize V7000 ports
To obtain the best overall performance of the subsystem and to prevent overloading, the 
load of each Storwize V7000 port should be equal. Assuming a similar load is generated 
by each host, you can achieve this balance by zoning approximately the same number of 
host ports to each Storwize V7000 port.
Figure 3-4 on page 56 shows an example of a balanced zoning configuration that was 
created by completing the following steps:
1. Divide ports on the I/O Group into two disjoint sets, such that each set contains two ports 
from each I/O Group node, each connected to a different fabric.
For consistency, use the same port number on each I/O Group node. The example that is 
shown in Figure 3-4 on page 56 assigns ports 1 and 4 to one port set, and ports 2 and 3 to 
the second set. 
Because the I/O Group nodes have four FC ports each, two port sets are created.
2. Divide hosts attached to the I/O Group into two equally numerous groups.
In general, for I/O Group nodes with more than four ports, divide the hosts into as many 
groups as you created sets in step 1.
3. Map each host group to exactly one port set.
4. Zone all hosts from each group to the corresponding set of I/O Group node ports. 
The host connections in the example on Figure 3-4 on page 56 are defined in the following 
manner: 
– Hosts in group one are always zoned to ports 1 and 4 on both nodes.
– Hosts in group two are always zoned to ports 2 and 3 on both nodes of the I/O Group.
The use of this schema provides four paths to one I/O Group for each host, and helps to 
maintain an equal distribution of host connections on Storwize V7000 ports.
Tip: Create an alias for the I/O Group port set. This step makes it easier to correctly zone 
hosts to the correct set of I/O Group ports. It also makes host group membership visible in 
the FC switch configuration.
Tip: To maximize performance from the host point of view, distribute volumes that are 
mapped to each host between both I/O Group nodes.