Configurations: Two types Users Configs: this is kept in their home so no need to worry aboutthat as normal backup takes care of it (exception can be
Data: By in large this is also maintained in homes, for that too backup software is the key. Data could also include software that either you made the mistake of building locally without some kind of packaging to repeat, or, that is 3rd party. Scripts and Cron Jobs also fall into this realm along with logs.
OS: That's why they make CD's. You just install. To make sure you get all of the same software, both rpm based, and deb based systems have ways of taking an inventory and replicating the inventory to another box.
There is no concept of registry in a Linux box. (unless you run some of the newer gnomes but that registery is by user so it's in the home.) This means you don't have to have restoreable clones to re-create the box. It's sufficient to have a copy of
On the cheap tar and gzip are all the tools needed. More involved. Puppet
The reason computer chips are so small is computers don't eat much.