[git] Reduce git repository size

git gc --aggressive is one way to force the prune process to take place (to be sure: git gc --aggressive --prune=now). You have other commands to clean the repo too. Don't forget though, sometimes git gc alone can increase the size of the repo!

It can be also used after a filter-branch, to mark some directories to be removed from the history (with a further gain of space); see here. But that means nobody is pulling from your public repo. filter-branch can keep backup refs in .git/refs/original, so that directory can be cleaned too.

Finally, as mentioned in this comment and this question; cleaning the reflog can help:

git reflog expire --all --expire=now
git gc --prune=now --aggressive

An even more complete, and possibly dangerous, solution is to remove unused objects from a git repository


Update Feb. 2021, eleven years later: the new git maintenance command (man page) should supersede git gc, and can be scheduled.