> Victor Sudakov wrote: > > In FreeBSD, you can always run "pkg delete -a" and return to the > > post-install state (well, almost). This command will remove all the > > third-party packages added to the base system after installation > > (modified files under /usr/local/ will remain).
That's because (Free|Open)BSD has a completely different approach to how they develop their operating system. Under their model, there are two completely *separate* parts of the operating system: the base system, and packages. Packages are add-ons that are maintained by a separate group. They're not part of the base system. They're installed in /usr/local, and they're tracked separately. In Debian, there is no such separation. There are only "packages", and these packages can be essential (what you'd consider part of the base system), or frivolous, or anywhere in between. The packaging system doesn't *know* which packages you would consider to be keep-worthy and which ones you would consider to be fluff. Only you would know that. So, if you want to put the work in to achieve this goal, you can come up with a set of packages that *you* consider important enough to keep, and then simply purge everything else. When you break the system, you will get to reinstall from scratch, which is what you should have been doing in the first place, if you really want to "clean up" a legacy installation.