For a long time I have used a single dns server. Now I want to create a secondary dns server to use as backup. I can create slave zones manually for all my domains and they get updated correctly. But it's unclear to me how to clone the whole dns server so that when a new zone is created on the primary server, the zone will be created accordingly on the slave one.
I can create a few scripts that periodically check on the master one for new zones and upload on the slave what is needed to create the slave zone. Is there any more clean method to do this?
I'm using two CentOS machine with BIND.