Reducing the repository size using Git

A GitLab Enterprise Edition administrator can set a repository size limit which will prevent you to exceed it.

When a project has reached its size limit, you will not be able to push to it, create a new merge request, or merge existing ones. You will still be able to create new issues, and clone the project though. Uploading LFS objects will also be denied.

In order to lift these restrictions, the administrator of the GitLab instance needs to increase the limit on the particular project that exceeded it or you need to instruct Git to rewrite changes.

If you exceed the repository size limit, your first thought might be to remove some data, make a new commit and push back to the repository. Unfortunately, it's not so easy and that workflow won't work. Deleting files in a commit doesn't actually reduce the size of the repo since the earlier commits and blobs are still around. What you need to do is rewrite history with Git's filter-branch option.

Note that even with that method, until git gc runs on the GitLab side, the "removed" commits and blobs will still be around. And if a commit was ever included in an MR, or if a build was run for a commit, or if a user commented on it, it will be kept around too. So, in these cases the size will not decrease.

The only fool proof way to actually decrease the repository size is to prune all the unneeded stuff locally, and then create a new project on GitLab and start using that instead.

With that being said, you can try reducing your repository size with the following method.

Using git filter-branch to purge files

Warning: Make sure to first make a copy of your repository since rewriting history will purge the files and information you are about to delete. Also make sure to inform any collaborators to not use pull after your changes, but use rebase.

1. Navigate to your repository:

   cd my_repository/

2. Change to the branch you want to remove the big file from:

   git checkout master

3. Use filter-branch to remove the big file:

   git filter-branch --force --tree-filter 'rm -f path/to/big_file.mpg' HEAD

4. Instruct Git to purge the unwanted data:

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

5. Lastly, force push to the repository:

   git push --force origin master

Your repository should now be below the size limit.

Note: As an alternative to filter-branch, you can use the bfg tool with a command like: bfg --delete-files path/to/big_file.mpg. Read the BFG Repo-Cleaner documentation for more information.