Need help tweaking WHM on Centos server

Hi, we have the following things needed done urgently: 1. We would like backup to be configured to tranfer to external server, or best possible, most secure backup on current server. 2. A partition is filling up on server, so we need to find out why and solve this problem. 3. The outgoing smtp mailserver stopped working (maybe due to low ressources?) 4. we soon must update MySQL and WHM without any data loss Its urgent so only make bid if u have time. thx