HP XP External Storage Software - Manual (Page 29)

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.
External Storage XP user guide for the XP12000, XP10000, SVS200 29