HP XP External Storage Software - Manual (Page 31)

Figure 7 Alternate path mode is Single mode with alternate paths in Normal and Standby
NOTE:
External arrays with Asymmetrical Active/Active (AAA) controllers, such as the Hitachi Thunder,
are an example of
Figure 7 . A notable characteristic of using AAA controller arrays as external
storage is that paths to alternate ports on the owning controller for a given external LU are seen
as Normal status, but I/O load balancing does not occur (either across controllers or across ports
to the owning controller). Paths to the non-owning external controller's ports are shown as Standby
status.
External Storage XP user guide for the XP12000, XP10000, SVS200 31