HP StorageWorks External Storage XP user guide (T1706-96006, June 2006)

26 Preparing for External Storage XP operations
NOTE: When the external array is an EVA array, as you restore the path with the highest priority,
the I/O execution path switches back to the restored highest priority path. In this case, the status of
the path for which the status changed to Normal when the error occurred changes back to
Standby.
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.