git rewrite history - How to remove old versions of media files from a git repository

Question

I have a Git repository with several huge media files (images and audio files). Several versions of these media files have been successively commited to the repo. The files are successively refined versions of the same assets, and they have the same name.

I want to keep only the latest version in the Git repository, because it is becoming too big.
What is the simplest way to do this?
How can I propagate these changes correctly to the upstream repository?

Answer 1

Old thread but in case someone else stumbles along here…

GitHub & Bitbucket both recommend using BFG Repo-Cleaner.

See:
GitHub: Remove Sensitive Data
Bitbucket: Reduce Repository Size & Bitbucket: Maintaining a Git Repository

Example to remove files over 1 Megabyte, as well as jpgs, pngs and mp3s that are not in HEAD:

# First get the latest bfg.jar, then:
$ git clone --mirror git://example.com/some-big-repo.git
$ java -jar bfg.jar --strip-blobs-bigger-than 1M --delete-files '*.{jpg,png,mp3}' some-big-repo.git
$ cd some-big-repo.git
$ git reflog expire --expire=now --all && git gc --prune=now --aggressive
$ git push

Note: now you've pushed the updated revs, the remote repository should also run it's git gc …else you won't see the size reduction. (see e.g. https://stackoverflow.com/a/28782154/3419541)

Finally, re-clone the repository to be sure that you don't accidentally re-commit the old media file blobs.