I manage several Linux servers for clients in several roles like email, caching, web serving, filtering, firewalling/routing, and so on.
Since I don't own these computers and just provide remote support, central management systems like Puppet don't seem like they are the correct tool. (Please correct me if you think I am wrong about this assumption)
What tools do you recommend to track changes of configuration files, package installs and so on?
I am thinking something like etckeeper may be near to what I need, but I want to know if there is something better.
Update
We will have backups of the systems, and I wouldn't expect this type of a tool to be an alternative to a backup. This is about keeping track of changes of configuration and having a system to know what changed when, by who, and hopefully why.