I'm currently trying to get an image working for a network boot using somebody else's file contents. The previous images I made keeping all original files present were way too big, so I need to shrink down the size of the necessary directories. Looking through the contents of these directories though, like /bin, /dev, /etc, etc., I really can't tell what's crucial to the system versus what is extra stuff specific to certain programs that were installed (which are not needed on the image). I don't want to delete anything important, though. The biggest directories by far are /etc, /lib, and /usr, all hundreds of MB larger than the equivalent directories of an image I previously got to work in the past. Because of this, I know that there's a lot of extra stuff in these directories. At the same time, I'm using a different operating system version (SL5 instead of SL4) so I'm not sure about comparing and contrasting those, especially since the filesystems had different things installed on them anyway.  Is there a quicker way to either sort what's needed versus what isn't, or to delete a lot of the extra crap files? (E.g. one recommendation was to delete everything labelled as documentation, but that's still not enough.)
How to determine which files are necessary in /bin, /lib, /var, etc.?
files;filesystems;memory