maintenance mode - configure number of simultaneous vmotions/migrations

Hello,

I am looking to understand and possibly tune the number of vmotions/migrations that ocurr at the same time during the following events:

1. Enter maintenance mode

2. Host failure

I see this article but is that just for manual operations such as selecting multiple guests and hitting migrate in vsphere client?

http://rcmtech.wordpress.com/2010/10/08/change-number-of-simultaneous-vmotion-operations-in-vsphere-4-1/

I appreciate the clarification.