Be aware that there is a bug when you want to create an override on the resource group rollup monitor to change the maintenance mode behavior! Let’s see: In my example I have one cluster with 2 cluster nodes. I needed to do some maintenance on my nodes and they needed to be rebooted. So I put one node in maintenance mode so that my NOC team will not get alerted, do what I had to do and finally restarted my node and do the same for the other node. Suddenly I had someone of the NOC team yelling...(read more)

Read the complete post at http://scug.be/blogs/scom/archive/2009/12/04/opsmgr-bug-console-crashing-when-creating-an-override-on-cluster-resource-group-monitor.aspx