howto prepare automatic backups

Hi

Im looking how to prepare automatic backups to openldap database. In last mail I comment problem with a crash report, and Im testing how can I do backups and restore it. Only I view slapcat command, but you need to stop the database, and is a critical server and I can't do this stop without create problems to users. There is not any other form?

And for other part I would like to understand the content of every folder, because Im with a ubuntu 9.04 server and Im checking what folder I need to control for future restores. Can someone explain the funcition of /var/lib/ldap and /etc/ldap/???

Where is the users data?

Thanks