Today I was trying to free some space on my server and came across my kernel sources which were a space hog here – especially if they’re already compiled:

denkbrett src # du -sh linux-2.6.39.3
718M    linux-2.6.39.3
denkbrett src # cd linux-2.6.39.3
denkbrett linux-2.6.39.3 # make distclean
denkbrett src # du -sh
437M    .

As you see, a ‘make distclean’ run saves you quite some space if you don’t want to remove the whole directory. Downside: You need to compile anything again if needed.