HP XP Racks - Manual (Page 30)

Figure 2-4 Position of the HDLM Driver and hdisk
Distributing a Load Using Load Balancing
When the system contains multiple paths to a single LU, HDLM can distribute
the load across the paths by using multiple paths to transfer the I/O data.
This function is called load balancing, and it prevents a single, heavily loaded
path from affecting the performance of the entire system.
Figure 2-5 Flow of I/O Data When the Load Balancing Function Is Not Used on
page 2-9 shows the flow of I/O data when the load balancing function is
not used. Figure 2-6 Flow of I/O Data When the Load Balancing Function Is
Used on page 2-10 shows the flow of I/O data when the load balancing
function is used. Both figures show examples of I/O operations being issued
for the same LU by multiple applications.
2-8
HDLM Functions
Hitachi Dynamic Link Manager (for AIX) User Guide