A. Persistent mode sets the initial state of a resource or group when the cluster service starts. By turning off persistent mode for a resource or group, you'll stop the resource or group from starting when the cluster service starts.
Auto start relates to the action to take during a failover operation. If you disable auto start for a resource or group, that resource or group won't start up during a failover. This setting could be useful if you have multiple virtual machines (VMs), some of which are less important than others. By disabling auto start for the less important VMs, you would allow the priority VMs to start uncontested.
In summary, persistent mode sets the resource's initial state and auto start configures what the resource will do in a failover situation.Related Reading: