Currently we have two 6509 Cat with 1 FWSM running in each switch in Active/Active mode. 6509-1 is the active box. We will be moving into a new data center that will also have 2 new 6509 equipped with FWSM. Both Data Centers will be trunk to simulate 1 virtual data center and once the migration is complete, old data center will be shut down. I'm trying to figure out how to migrate over the FWSM without some sort of downtime. The only thing i can think of at this time, is offline the standby FWSM at the old data center and remove failover all together and at the new data center, on a new 6509 equipped with FWSM establish failover with the active FWSM located in the old data center. Then promote standby FWSM in new data center to active. What do you think about this procedure?