UPDATE: The migration was successful. Everything should be working properly and with better performance.
Tonight 1-17-2013 at 11:59 pm we will be migrating one of our MySQL servers (b.custsql) to new hardware. We estimate downtime should be 30 minutes to 1hr. This database server will be unavailable to sites at this time. At the same time we will be enforcing our current policy of not allowing MySQL connections to this server from systems other than our web and shell servers.