Is there any fast and reliable way to remove everything not related to OS from the server?
In removing everything I mean:
In general I'm interested to do this thing on Debian and CentOS based servers.
If there's no a "fast and reliable" way to do it with one or several commands, then please explain how to do it manually.
If you're trying to go back to a clean system, as in "fresh install", you need to do a fresh install. Or if you were prescient enough to bare-metal image the system immediately after install, you could go back to that.
Even with Linux's package systems there are configurations and settings that may not be removed in a remove or uninstall. Especially in a server environment, when you need a clean install you cannot simply remove everything you did since the install. You have to cleanly install to get to a clean install state.
UPDATE: Cleaning packages
Ramii.org has some tips for listing packages and cleaning unused packages in a debian system: http://raymii.org/s/tutorials/Debian-apt-get-dpkg-packages-cleanup-commands.html
To list the installed packages:
dpkg --get-selections | cut -f1 | while read pkg; do dpkg -L $pkg | xargs -I'{}' bash -c 'if [ ! -d "{}" ]; then echo "{}"; fi' | tr '\n' '\000' | du -c --files0-from - | tail -1 | sed "s/total/$pkg/"; done | sort -rn > ~/packages.log.txt
He goes on to list methods of listing config files not removed during apt remove processes.
Once you've removed all the packages you wish, run:
apt-get autoremove
and
apt-get clean
to clean the repositories and unused apt files.
If you remove packages one by one since there is no easy way to do so, make sure to "purge" them. That is, if you are in Debian, "aptitude purge packaged" to remove all configuration files. Then there is also "aptitude autoremove" to remove unnecessary dependencies.
On Debian, you can use the 'deborphan' tool to list packages that have no packages depending on them, so they often can be removed unless you really know you need them. As with all packaging tools: use with caution.
