# Management Servers for HA

When a Management Server is active, the Management Server has control of all Domains and can be used for configuring and managing the SMC. Only one Management Server at a time can be the active Management Server.

The changes made on the active Management Server are replicated incrementally to the other Management Servers: only the changed parts of the management database are replicated, and the replication takes place in real time.

To use additional Management Servers, you must have a special Management Server license that includes the high availability feature. The license is a combined license for all Management Servers and it must list the IP addresses of all Management Servers.

Additional Management Servers automatically replicate the configuration data on the active Management Server. If the active Management Server becomes unusable, you must manually activate another Management Server, which allows you to work normally.

Note: The additional Management Servers are meant for backup and disaster recovery purposes. Only one Management Server at a time can be used for configuring and managing the SMC.