A Guide to Why Git LFS Repos Can Be Larger

Understanding Git LFS Repository Size

I ran into an intriguing problem while switching a sizable SVN repository to Git. The size of the Git repository greatly expanded when it was converted to use Git LFS for storing binaries.

This article investigates whether conventional Git packs binaries more efficiently than Git LFS and why the migrated Git LFS repository ends up larger than the original. In addition, I'll go over the commands and procedures utilized in the migrating process.

Understanding the Migration Scripts

A Git repository can be automatically migrated to use Git LFS with the use of a Bash script. It starts by setting up LFS and using the git lfs track command to track binary files. Subsequently, the tracking configuration is incorporated into the repository and committed. To effectively remove old binary files from the main Git history, use the bfg --convert-to-git-lfs command to convert them to LFS within the repository. Following this conversion, the script executes git reflog expire and git gc --prune=now in order to reduce the size of the repository by pruning superfluous files and expiring outdated references.

This is enhanced by the Python script, which offers a means of comparing repository sizes prior to and following migration. It runs the du -sh command to obtain the disk use of the designated directories by utilizing the subprocess.run function. This makes it possible to compare the repository sizes before and after the LFS migration in a transparent manner. The report confirms the efficacy of the migration process by illuminating how the cleanup and migration commands affect repository size.

#!/bin/bash
# Step 1: Initialize LFS and track file type
git lfs install
git lfs track "*.bin"
git add .gitattributes
git commit -m "Track binary files with LFS"
# Step 2: Migrate existing files to LFS
bfg --convert-to-git-lfs '*.bin' --no-blob-protection
git reflog expire --expire=now --all
git gc --prune=now --aggressive

import subprocess
def get_repo_size(path):
    result = subprocess.run(['du', '-sh', path], stdout=subprocess.PIPE)
    size = result.stdout.split()[0].decode('utf-8')
    return size
before_migration = get_repo_size('/path/to/repo_before_lfs')
after_migration = get_repo_size('/path/to/repo_after_lfs')
print(f"Size before LFS migration: {before_migration}")
print(f"Size after LFS migration: {after_migration}")

Examining Git LFS's Effect on Repository Size

Understanding how Git and Git LFS manage file storage differs is a crucial part of moving to Git LFS. Git LFS stores the actual contents of files independently and substitutes huge files in your repository with tiny pointer files. Because of this separation, there may be a brief increase in the on-disk size during the migration process because both the old LFS pointers and the huge files will still be present. Git LFS has alternative compression and storing techniques, which may or may not lead to reduced repository sizes, particularly just after migration. This is another factor.

It's important to run commands like git reflog expire and git gc --prune=now --aggressive in order to optimize the repository size after migrating. By removing pointless files and references, these procedures greatly reduce the size of the repository. In order to maintain the repository efficient, it's also critical to periodically check its size and carry out maintenance. An effective relocation procedure can be ensured and expectations can be managed with the help of these subtleties.

Concluding Remarks on the Git LFS Migration

Because original files and LFS pointers coexist, the conversion to Git LFS may cause a brief rise in repository size. Nevertheless, the size can be greatly decreased by executing maintenance instructions like git reflog expire and git gc --prune=now --aggressive. For a migration to be successful, it is essential to comprehend how Git and Git LFS manage file storage differently.

The long-term advantages of using Git LFS, particularly for remote storage and cloning efficiency, exceed the short-term drawbacks, even though the first size increase may be unsettling. An ideal and manageable repository size can be achieved with routine maintenance and appropriate configuration.