For test the failover manually, I reboot the Node 0 (primary). Then the Node 0 back to up, but I notice the Node 0 is secondary still. The node should change automatically to primary or I must be manually?
You must failover the node manually for both RG0 and RG1+ group. If you would like to perform the automatic failover back to the node whose priority is higher then you gotta configure preempt option. Please note that preempt option is available only for RG1+ group and not for RG0. So, you should manually failover the RG0 anyway.
Ok, I´m going to configure preempt option for RG1 and I´ll test again.
Generally the recommendation is to manual fail back after a failure event. The reason is for someone to verify the issue causing failover in the first instance is resolved and the system is stable.
The danger is that if there is an ongoing or intermittent issue and you have revert configured with preempt you can end up with a flapping of failovers back and forth continuously until the issue is resolved.
If you do configure preempt be sure to select a long enough period of time to be reasonably confident any issue has indeed cleared to prevent such flapping.