I have an OpenLDAP server running on a Debian machine that serves logins to various machines. I would like to create a backup server, which simply keeps a copy of all the OpenLDAP data so that in case the original server fails, the backup server can start serving logins once its IP is changed to that of the original server and the OpenLDAP server is started on it.
How can this be done? Or is it recommended to create a slave OpenLDAP server? If I create a slave server, will all the client machines that have already been configured (over 40 of them) need extra configuration to know about the slave server?