I have a client who asked me to set up a Lion email server for 20 users all over the world. It is running open directory for the user accounts and has a wiki set up on it as well. I have been researching backup solutions for it. The server runs in a remote data center environment and it is the only mac on the network. There are other Linux and windows machines on the same network as well. I would like a backup solution for the email and open directory database that doesn't require stopping the email service (if possible), and I would like to back up over the network (if possible). What would be the best way to back up this server considering it needs to be in service 24/7? I am open to both free and commercial solutions. Any thoughts or comments would be very much appreciated.