ETC5513: Collaborative and Reproducible Practices

Workshop 7

Author

Michael Lydeamore

Published

20 May 2025

Workshop: Git LFS, Big Files, and Recovery

🧭 Goal

Understand: - Why Git can’t handle big files normally - How to recover if you accidentally try to commit something too big - The basics of Git LFS

Setup

  1. Create a new GitHub repository:

    git-lfs-practice

  2. Clone it to your computer using RStudio:

    • File → New Project → Version Control → Git
    • Paste the repo URL

Simulate a Mistake: Add a Huge File

1l. Download the zip file from the Week 8 Moodle website

Try to Commit the Huge File

  1. Stage bigfile.txt
  2. Try to commit it.

🔵 Expected Result:
GitHub will likely reject the push (file too large >100MB), or your Git client will warn you.

✅ You’ve hit a real size limit!

Try to Fix It With git revert

  1. Try to revert the bad commit:

    git revert HEAD

🔵 Expected Result:
Git won’t let you — because the giant file is still in the commit history.

⚠️ Key point: git revert adds new commits; it doesn’t erase old ones.

Actually Fix It With git reset

  1. Do a soft reset to move back before the bad commit:

    git reset --soft HEAD~1

  2. Now unstage the big file manually in RStudio (or):

    git restore --staged bigfile.txt

  3. Delete bigfile.txt from your project folder.

  4. Commit the new clean state:

    "Remove large file after reset"

Install Git LFS

  • Install Git LFS:
    Follow instructions here → https://git-lfs.github.com/

  • Track large files safely:

    git lfs install
git lfs track "*.csv"

  • Then commit/push files as usual — Git LFS manages the storage.

Summary

Problem Solution
Committed a huge file git reset + delete manually
Need to work with big files safely Use Git LFS

🎉 You survived a Git crisis — just like real developers do!