I ordered a handfull (about 10) of servers for my startup and I was wondering if there exist a good tool to clone servers. (espcecially propagating changes in configurations/installed programs)

All my servers are identical in terms of hardware and I would like to be able to install/upgrade/remove programs/libraries or change configuration files on one master server, which should then be overtaken by all the slaves (about 10 servers), without me making the same changes on all the other slaves.

Private keys can also be copied, as no private information/user data is being kept on the different servers.

One thing I was thinking about was rsync'ing / (except /proc, /log and the data directories) to all the servers, so they are uptodate. But I don't know if this will work reasonably well. (This might not work after a kernel update)

What are your thoughts on this? There are certainly other people out there who have done something similar. (Also some applications have to be compiled, so I can not build a snapshot of the packages I have installed from the repository of the linux distribution.)