How to fix Auto packing the repository in background for optimum performance in Git

In most cases, the best action is to do nothing and let Git finish its work. The background gc process typically completes within seconds to a few minutes, depending on repository size.

Verify gc is running in background:

# Check for running git processes (Linux/macOS)
ps aux | grep "git gc"

# On Windows PowerShell
Get-Process | Where-Object { $_.ProcessName -like "*git*" }

If you see git gc --auto running, simply wait for it to complete. The message should stop appearing once maintenance catches up.

If the message appears repeatedly or you want to proactively optimize your repository, run gc manually:

# Standard garbage collection
git gc

# Aggressive optimization (takes longer, better compression)
git gc --aggressive

# Force gc even if not needed
git gc --force

For thorough cleanup after large repository changes:

# Remove unreachable objects older than 2 weeks
git gc --prune=now

# Or run prune separately first
git prune
git gc

Warning: --prune=now removes all unreachable objects immediately, which means you lose the ability to recover recently deleted branches or reset commits. Only use this if you're sure you don't need to recover anything.

If gc runs repeatedly without success, check for a gc.log file that may be blocking further automatic runs:

# Check if gc.log exists
cat .git/gc.log

# If it exists and shows old errors, remove it
rm .git/gc.log

# Then run gc manually
git gc

Git creates .git/gc.log when automatic gc fails. This file prevents repeated failed attempts, but can become stale if the underlying issue was resolved. Removing it allows gc --auto to try again.

Dangling objects (unreferenced commits, blobs, or trees) can trigger frequent gc runs. Check for them:

# Find dangling objects
git fsck --unreachable

# More detailed output
git fsck --lost-found

If you see many dangling objects, this is normal after rebases, resets, or force pushes. They'll be cleaned up when gc runs successfully. If they persist:

# Force cleanup of unreachable objects
git reflog expire --expire=now --all
git gc --prune=now

Caution: This removes your ability to recover previous states via reflog. Only do this if you're sure you don't need to recover anything.

If the message appears too frequently or you want to control when gc runs, adjust the thresholds:

Increase threshold (fewer auto gc runs):

# Increase loose object threshold (default: 6700)
git config gc.auto 10000

# Increase pack limit (default: 50)
git config gc.autoPackLimit 100

Disable automatic gc entirely:

# Disable auto gc (you must run git gc manually)
git config gc.auto 0

Run gc in foreground instead of background:

# Disable background execution
git config gc.autoDetach false

These settings can be set globally with --global or per-repository. Remember that disabling auto gc means you're responsible for running it periodically.

In CI/CD environments, the message can clutter logs. You have several options:

Option 1: Redirect message to /dev/null

git fetch 2>&1 | grep -v "Auto packing"

Option 2: Disable auto gc for CI

# In your CI script
git config gc.auto 0
git fetch origin
# Run gc explicitly when needed
git gc

Option 3: Use git with quiet mode where available

git fetch --quiet

Note that --quiet suppresses some but not all messages. For complete control, consider option 1 or 2.

If you're seeing this message on nearly every Git operation, you may have a bug from older Git versions:

# Check your Git version
git --version

A bug in Git versions before 2.20 could cause excessive loose objects to accumulate because gc wasn't cleaning up properly. This was fixed in Git 2.20.0.

Upgrade on Ubuntu/Debian:

sudo add-apt-repository ppa:git-core/ppa
sudo apt update
sudo apt install git

Upgrade on macOS:

brew upgrade git

Upgrade on Windows:
Download the latest installer from https://git-scm.com/download/win

After upgrading, run git gc once to clean up accumulated objects.