I built up a samba4 active directory domain controller on ubuntu 14.04 and everything is working fine. The Windows clients can log in and do stuff. So far so good.

However, in case of emergency, I want to have a second samba4 ad dc, which will take the place of the first one. Both should be "identically" concerning functionallity and data up-to-dateness.

Is it possible to run two samba4 ad dc servers parallel, which are communicating with each other, and if one goes down, the other one is replacing the "main" server ? If so, how to achieve this goal? Any suggestions?

Thank you in advance