In a Database Availability Group (DAG), if your databases are randomly mounting or flipping from one server to another, for no apparent reason (including across datacenters) you may be suffering from your network interface card (NIC) going to sleep. And that’s not a good thing.
Mike blames power management. (But I blame society):
In the power management settings for the NIC on Windows Server, make sure you are not allowing the NIC to go into power save mode. Why is this important? It seems like at least once a month I’ve run into customers who have this power management setting turned on and more than one of them even had it turned on for their replication network.
While on power management related topics, if you haven’t seen Scott Hanselman’s excellent summation of all things power management, combining internal comment and external content, take a look here.
Posted by MSPFE Editor and PFE Without His Usual Posting Templates Because Of Yet Another New Laptop, Tristan Kington