How to fix error: could not lock config file: Input/output error (WSL filesystem issue) in Git

The most reliable fix is to store your Git repositories on the Linux filesystem instead of the Windows filesystem. WSL 2 stores Linux files in a virtual disk that doesn't have interoperability issues.

Move your repository:

# Create a projects directory in your Linux home
mkdir -p ~/projects

# Copy the repository from Windows to Linux
cp -r /mnt/c/Users/YourName/projects/your-repo ~/projects/

# Navigate to the new location
cd ~/projects/your-repo

# Verify Git works
git status

Access Linux files from Windows:
You can still access your Linux files from Windows via:

\\wsl$\Ubuntu\home\yourusername\projects

This path works in File Explorer and most Windows applications.

Performance bonus: Git operations on the Linux filesystem are significantly faster (often 5-10x) compared to accessing Windows files through /mnt/.

If you must keep repositories on the Windows filesystem, enable metadata support in WSL to improve file permission handling.

Create or edit /etc/wsl.conf:

sudo nano /etc/wsl.conf

Add these options:

[automount]
enabled = true
options = "metadata,umask=22,fmask=11"
root = /mnt/

[interop]
enabled = true
appendWindowsPath = true

Explanation:
- metadata: Stores Linux permissions as NTFS extended attributes
- umask=22: Sets default permissions for directories (755)
- fmask=11: Sets default permissions for files (644)

Restart WSL for changes to take effect:

# In PowerShell (as Administrator)
wsl --shutdown

# Then reopen your WSL terminal

After restarting, try your Git operations again.

Windows Defender and other antivirus software can interfere with Git operations by holding file locks during scanning.

Add exclusions in Windows Security:
1. Open Windows Security (search "Windows Security" in Start menu)
2. Go to "Virus & threat protection"
3. Under "Virus & threat protection settings", click "Manage settings"
4. Scroll to "Exclusions" and click "Add or remove exclusions"
5. Add folder exclusions for:
- Your Git repositories folder
- C:\Users\YourName\.gitconfig
- WSL installation: %LOCALAPPDATA%\Packages\CanonicalGroupLimited.Ubuntu*

Or via PowerShell (as Administrator):

# Exclude your projects folder
Add-MpPreference -ExclusionPath "C:\Users\YourName\projects"

# Exclude WSL distribution
Add-MpPreference -ExclusionPath "$env:LOCALAPPDATA\Packages\CanonicalGroupLimited.Ubuntu*"

# Verify exclusions
Get-MpPreference | Select-Object -ExpandProperty ExclusionPath

For third-party antivirus, consult your antivirus documentation for adding folder exclusions.

OneDrive, Dropbox, Google Drive, and other cloud sync services can cause file locking conflicts with Git.

For OneDrive:
1. Right-click the repository folder in File Explorer
2. Select "Free up space" or "Always keep on this device" to prevent sync conflicts
3. Or move the repository outside OneDrive folders entirely

Better approach - use .gitignore for sync services:
If your repository is in a synced folder, the sync service may conflict with Git's internal files.

Exclude Git internals from OneDrive:

# In PowerShell, add .git folders to OneDrive exclusion
# Note: OneDrive doesn't have built-in folder exclusion, so moving is preferred

Best practice: Keep Git repositories in a non-synced folder:

# Move from OneDrive folder to a non-synced location
mv /mnt/c/Users/YourName/OneDrive/projects /mnt/c/Users/YourName/projects

# Or better yet, move to Linux filesystem
mv /mnt/c/Users/YourName/OneDrive/projects ~/projects

OneDrive and Git both track file changes, and they don't play well together. Use one or the other, not both.

The "Input/output error" can indicate underlying disk problems on Windows.

Check disk space:

# Check Windows drive space from WSL
df -h /mnt/c

# Check if the drive is nearly full
# Git needs space for temp files and lock files

Check disk health from Windows:

# In PowerShell (as Administrator)
chkdsk C: /F /R

# This will schedule a check on next reboot for the system drive

Check for NTFS errors:

# Repair Windows image issues
DISM /Online /Cleanup-Image /RestoreHealth

# Verify system file integrity
sfc /scannow

Check WSL disk image:

# WSL 2 uses a virtual disk - optimize it
wsl --shutdown
Optimize-VHD -Path "$env:LOCALAPPDATA\Packages\CanonicalGroupLimited.Ubuntu*\LocalState\ext4.vhdx" -Mode Full

If disk checks reveal errors, address them before continuing with Git operations.

If you must work with repositories on the Windows filesystem, consider using Windows Git instead of WSL Git.

Install Git for Windows:
Download from https://git-scm.com/download/win

Configure WSL to use Windows Git for Windows paths:

Create a wrapper script:

# Create ~/bin if it doesn't exist
mkdir -p ~/bin

# Create a smart git wrapper
cat > ~/bin/git-smart << 'EOF'
#!/bin/bash
# Use Windows Git for Windows paths, Linux Git otherwise
if [[ "$PWD" == /mnt/* ]]; then
    git.exe "$@"
else
    /usr/bin/git "$@"
fi
EOF

chmod +x ~/bin/git-smart

Add to your PATH in ~/.bashrc:

export PATH="$HOME/bin:$PATH"
alias git='git-smart'

Or simply use git.exe directly:

# When in /mnt/c/... paths
git.exe status
git.exe commit -m "message"
git.exe push

This approach uses Windows-native file operations and avoids the WSL filesystem translation layer entirely.

If the error persists and seems to be a WSL-level issue, updating or reinstalling WSL may help.

Update WSL:

# In PowerShell (as Administrator)
wsl --update

# Check WSL version
wsl --version

Convert to WSL 2 if using WSL 1:

# Check current version
wsl -l -v

# Convert to WSL 2 if needed
wsl --set-version Ubuntu 2

Reset WSL if corrupted:

# Export your data first!
wsl --export Ubuntu ubuntu-backup.tar

# Unregister the distribution
wsl --unregister Ubuntu

# Reinstall from Microsoft Store or:
wsl --install -d Ubuntu

# Restore your data
wsl --import Ubuntu C:\WSL\Ubuntu ubuntu-backup.tar

Alternative - clean reinstall:
1. Backup your Linux home directory
2. Uninstall Ubuntu from Windows Settings > Apps
3. Reinstall from Microsoft Store
4. Restore your files

After reinstalling, the filesystem interoperability layer will be reset to defaults.