Converting git repository to shallow?

Question

How can I convert an already cloned git repository to a shallow repository?

The git repository is downloaded through a script outside of my control so I cannot do a shallow clone.

The reason for doing this is to save disk space. (Yes, I'm really short on disk space so even though a shallow repository doesn't save much, it is needed.)

I already tried

git repack -a -d -f -depth=1

But that actually made the repository larger.

Answer 1

This worked for me:

git pull --depth 1
git gc --prune=all

This leaves the tags and reflog laying around, each of which reference additional commits that can use up space. Note that I would not erase the reflog unless severely needed: it contains local change history used for recovery from mistakes.

There are commands on how to erase the tags or even the reflog in the comments below, and a link to a similar question with a longer answer.

If you still have a lot of space used you may need to remove the tags, which you should try first before removing the reflog.