You typically want to spread as wide as you can when it comes to using front end ports. So if you only have a single engine, for a given host/LUN assign it to a port on both directors. If you have multiple engines you might want to spread across both engines. This is for performance and redundancy. Check out some examples on page 25 and 26 in this techbook for VMware and Symmetrix:  [URL]  Might be using a different host, but the idea remains the same for connectivity.
Still getting used to the symmetrix world and am running into an issue.  we have an emc hardware issue that requires a board be replaced.  EMC came out today and ran their script to validate HA and found some boot lunes that dont have alternating paths:  [IMAGE]  Should someone have configured the port group so that is uses a FA port from each director VS two from the same and is that whats causing the script to trigger an issue?
VMAX 10K Single Engine (Port Group Question)