Hi,
Thanks for the reply.
I have not tried rebooting the controller and switch yet. I have tried moving the preferred controller.
What I can see so far from the ESXi perspective is 4 active paths, two with IO only to the preferred controller. If I reallocate the preferred controller the Active IO changes to the other two paths in ESXi. This seems correct.
If I create a situation where there is only a path to the non preferred controller by unplugging cables, then I get Active IO through the non preferred controller. This seems correct too as the ALUA stuff I think takes the path of greater latency in order to continue IO as the controllers do not know to change preferred controller.