HP StorageWorks XP External Storage user guide: HP XP12000 Disk Array, HP XP10000 Disk Array, HP 200 Storage Virtualization System (T1706-96017, June 2010)

Figure 5 Alternate path mode is Multi mode
.
Note : In Multi mode, active I/O load balancing occurs across external array ports and controllers.
The XP and EMC DMX are examples of external arrays that use Multi mode.
• Alternate path mode is Single mode.
Figure 6 shows an example of when the alternate path mode is Single mode. When an error occurs
in the path used for I/Os, the I/O execution path switches to the path with the second highest
priority.
Note : As you restore the path with a priority higher than the current path, the I/O execution path
automatically switches to the restored path with the highest priority.
Preparing for XP External Storage operations28