Upgrading SCOM 2007 R2 CU3 to CU7. Multiple management groups with shared data warehouse.

Hello,

Looking to begin upgrading SCOM 2007 R2 CU3 to CU7 in preparation for a move towards 2012 SP1. We currently have two management groups sharing the same data warehouse. When we go to upgrade do both management groups have to upgraded at the same time? Can we upgrade MG1 and then follow up with MG2 at a later date or must they all be completed at the same time?

Thanks,

Jim