repository-layout Git Repository Structure Guide

The git repository-layout documentation describes the structure and organization of Git repositories, including directory layouts, file purposes, and repository types.

Repository Types and Structures:

Repository Flavors:

Git Repository Types:
├── Working Directory Repository: .git/ at root of working tree
├── Bare Repository: <project>.git/ without working tree
├── Gitfile Repository: .git file pointing to real repository
└── Submodule Repository: Managed via git submodule/worktree

Repository Detection:
├── .git/ directory or file indicates Git repository
├── Bare repos have core.bare=true in config
├── Gitfiles contain "gitdir: <path>" format
└── Submodules use gitfiles for repository sharing

Directory Structure Overview:

Git Repository Layout:
├── .git/ (or <project>.git/)
│   ├── objects/          # Object storage
│   ├── refs/            # Reference storage
│   ├── HEAD             # Current branch pointer
│   ├── index            # Staging area
│   ├── config           # Repository configuration
│   ├── logs/            # Reflog storage
│   └── hooks/           # Git hooks
├── [working tree]       # Files (non-bare repos only)
└── .gitmodules         # Submodule definitions

Core Repository Components:

Object Storage (objects/):

Object Database Structure:
├── objects/
│   ├── [0-9a-f][0-9a-f]/    # Loose objects by SHA-1 prefix
│   ├── pack/                # Packed object archives
│   ├── info/                # Object database info
│   └── [custom]/            # Alternative object storage
│
├── Object Types:
│   ├── commit    # Commit objects
│   ├── tree      # Directory snapshots
│   ├── blob      # File contents
│   └── tag       # Annotated tags
│
└── Storage Details:
    ├── Loose: Individual files in subdirs
    ├── Packed: Compressed archives (.pack/.idx)
    ├── Alternates: Shared object storage
    └── Info: Packs, alternates, and skiplists

Reference Storage (refs/):

Reference Hierarchy:
├── refs/
│   ├── heads/              # Local branches
│   ├── remotes/            # Remote tracking branches
│   ├── tags/               # Tags
│   ├── notes/              # Notes
│   ├── replace/            # Object replacements
│   └── [custom]/           # Custom references
│
├── Reference Types:
│   ├── Symbolic: Point to other refs (HEAD)
│   ├── Direct: Point to objects (branches/tags)
│   └── Packed: Stored in packed-refs file
│
└── Special Refs:
    ├── HEAD: Current branch/commit
    ├── ORIG_HEAD: Pre-merge/reset state
    ├── MERGE_HEAD: Merge target
    └── CHERRY_PICK_HEAD: Cherry-pick target

Configuration Files:

Configuration Storage:
├── config                 # Repository-specific config
├── .gitmodules           # Submodule definitions
├── .gitattributes        # Path-specific attributes
├── .gitignore           # Ignore patterns
└── info/
    ├── exclude          # Global ignore patterns
    ├── attributes       # Global attributes
    ├── grafts           # Parent relationship overrides
    └── sparse-checkout  # Sparse checkout patterns

Index and Staging:

Staging Area Components:
├── index                 # Main index file
├── .git/index.lock       # Index lock file
└── [working tree]        # Working directory files

Index Contents:
├── File entries with stat info
├── Object IDs for staged content
├── Conflict resolution data
├── Untracked cache (optional)
└── Split index (optional)

Advanced Repository Features:

Packed References (packed-refs):

Packed References:
├── packed-refs           # Packed reference file
├── Format: <SHA-1> <ref-name>
├── Performance optimization
├── Automatic packing
└── Manual unpacking with git pack-refs

Packing Process:
├── Collect loose refs
├── Write to packed-refs
├── Remove loose ref files
└── Update reflogs

Reflogs (logs/):

Reflog Storage:
├── logs/
│   ├── HEAD              # HEAD movement history
│   ├── refs/heads/       # Branch reflogs
│   ├── refs/remotes/     # Remote reflogs
│   └── [custom]/         # Custom reflogs
│
├── Reflog Format:
│   ├── <old-sha> <new-sha> <user> <timestamp> <operation>
│   ├── Recovery mechanism
│   ├── Configurable expiration
│   └── Size limits
│
└── Reflog Operations:
    ├── git reflog show
    ├── git reflog expire
    └── git reflog delete

Hooks System (hooks/):

Git Hooks Directory:
├── hooks/
│   ├── pre-commit        # Before commit creation
│   ├── commit-msg        # Commit message validation
│   ├── post-commit       # After commit creation
│   ├── pre-push          # Before push operations
│   ├── post-receive      # After receive operations
│   └── [custom]          # Custom hooks
│
├── Hook Types:
│   ├── Client-side: pre-commit, commit-msg, etc.
│   ├── Server-side: pre-receive, post-receive, etc.
│   └── Special: post-rewrite, post-checkout, etc.
│
└── Hook Management:
    ├── Executable scripts
    ├── Exit codes control Git behavior
    ├── Environment variables available
    └── Hook chaining possible

Worktrees (worktrees/):

Worktree Storage:
├── worktrees/
│   ├── <worktree-name>/
│   │   ├── gitdir        # Path to main repo .git
│   │   ├── HEAD          # Worktree HEAD
│   │   ├── index         # Worktree index
│   │   └── [custom]      # Worktree-specific files
│
├── Worktree Features:
│   ├── Multiple working trees
│   ├── Shared object storage
│   ├── Independent branches
│   └── Sparse checkouts
│
└── Worktree Management:
    ├── git worktree add
    ├── git worktree remove
    ├── git worktree prune
    └── git worktree list

Repository Maintenance Areas:

Garbage Collection (gc/):

GC-Related Files:
├── .git/gc.log          # Last GC operation log
├── .git/shallow         # Shallow clone boundaries
└── .git/modules/        # Submodule repositories

GC Process:
├── Loose object packing
├── Reflog expiration
├── Unreachable object removal
└── Repository optimization

Submodules (modules/):

Submodule Storage:
├── modules/
│   ├── <submodule-name>/
│   │   ├── objects/     # Submodule objects
│   │   ├── refs/        # Submodule refs
│   │   └── [other]/     # Standard repo structure
│
├── Submodule Features:
│   ├── Nested repositories
│   ├── Independent histories
│   ├── Shared vs separate clones
│   └── Update strategies
│
└── Submodule Management:
    ├── .gitmodules file
    ├── git submodule commands
    └── Recursive operations

Custom Extensions:

Extension Areas:
├── rebase-apply/        # Rebase state
├── rebase-merge/        # Interactive rebase state
├── CHERRY_PICK_HEAD     # Cherry-pick state
├── MERGE_HEAD           # Merge state
└── [custom]/            # Tool-specific state

State Management:
├── Temporary operation state
├── Recovery information
├── Progress tracking
└── Cleanup on completion

Repository Inspection and Management:

Repository Analysis Commands:

# Inspect repository structure
find .git -type f | head -20                    # List all files
du -sh .git/*                                  # Directory sizes
git count-objects -v                           # Object statistics

# Reference inspection
git show-ref                                    # All references
git for-each-ref --format='%(refname)'         # Formatted refs
ls -la .git/refs/                               # Reference files

# Configuration inspection
git config --list --local                       # Local config
cat .git/config                                 # Raw config

Repository Maintenance:

# General maintenance
git gc --aggressive                            # Full garbage collection
git fsck --full --strict                       # Integrity check
git repack -a -d --threads=4                   # Repack objects

# Reference maintenance
git pack-refs --all                            # Pack references
git reflog expire --expire=90.days --all       # Clean reflogs
git update-ref --stdin                         # Bulk ref updates

# Index maintenance
git update-index --refresh                     # Refresh index
git update-index --really-refresh              # Force refresh

Repository Backup and Recovery:

# Repository backup
tar czf repo-backup.tar.gz .git/               # Full backup
git bundle create repo.bundle --all            # Bundle backup

# Repository recovery
git fsck --unreachable | grep commit           # Find lost commits
git update-ref refs/heads/recovered <commit>   # Recover refs
git reflog --all                               # Check reflog history

# Repository cloning
git clone --mirror <source> <backup>           # Mirror clone
git remote add backup <backup-url>             # Add backup remote

Repository Type Comparisons:

Working Directory vs Bare Repository:

Working Directory Repository:
├── .git/ at working tree root
├── Working files present
├── Can perform all operations
├── Default for development
└── git init creates this type

Bare Repository:
├── <project>.git/ directory only
├── No working tree
├── Push/fetch operations only
├── Server-side repositories
└── git init --bare creates this type

Key Differences:
├── Working tree: Present vs absent
├── Operations: Full vs limited
├── Use cases: Development vs sharing
└── Commands: All vs subset available

Traditional vs Modern Repository:

Traditional Layout:
├── All data in .git/
├── Single working tree
├── Simple structure
└── Standard operations

Modern Layout:
├── Worktrees for multiple trees
├── Submodules for composition
├── Alternates for sharing
├── Sparse checkouts
└── Advanced features

Evolution:
├── Git 1.x: Basic structure
├── Git 2.x: Worktrees, submodules
├── Current: Advanced features
└── Future: More optimizations

Troubleshooting Repository Issues:

Corrupted Repository Recovery:

# Diagnose corruption
git fsck --full                                # Check integrity
git fsck --unreachable                         # Find unreachable objects

# Recover from corruption
git reflog                                     # Check recent operations
git reset --hard HEAD@{1}                      # Go back one step
git update-ref -d refs/heads/corrupted         # Remove bad refs

# Rebuild corrupted index
rm .git/index                                  # Remove corrupted index
git reset --mixed HEAD                         # Rebuild index

Repository Size Issues:

# Analyze repository size
du -sh .git/                                   # Total size
du -sh .git/objects/                           # Objects size
du -sh .git/logs/                              # Reflog size

# Clean up large repositories
git gc --aggressive --prune=now                # Aggressive GC
git repack -a -d --depth=250 --window=250      # Deep repack
git reflog expire --expire=1.month --all       # Clean reflogs

Permission Issues:

# Fix permission problems
find .git -type f -exec chmod 644 {} \;        # File permissions
find .git -type d -exec chmod 755 {} \;        # Directory permissions
chown -R user:group .git/                      # Ownership

# Check permissions
ls -la .git/HEAD                               # Check key files
git status                                     # Test operations

Path Issues:

# Handle path problems
git config core.ignorecase false               # Case sensitivity
git config core.precomposeunicode true         # Unicode handling
git config core.protectHFS false               # HFS protection
git config core.protectNTFS false              # NTFS protection

# Check path encoding
locale                                         # System locale
git config --get gui.encoding                  # Git encoding

Configuration Corruption:

# Fix config issues
git config --list --local                      # Check current config
cp .git/config .git/config.backup              # Backup config
git config --unset-all <key>                   # Remove bad config
git config --replace-all <key> <value>         # Fix config

# Reinitialize config
rm .git/config                                 # Remove corrupted config
git init                                       # Reinitialize (keeps objects)

Advanced Repository Operations:

Repository Surgery:

# Advanced repository operations
git update-ref -d refs/heads/old-branch        # Delete refs
git update-ref refs/heads/new-branch <commit>  # Create refs
git replace <old> <new>                        # Object replacement
git filter-branch --tree-filter <command>      # History filtering

# Repository restructuring
git mv <old-path> <new-path>                   # Move files
git rm -r <old-dir>                            # Remove directories
git read-tree --prefix=<dir>/ <tree>           # Add subtrees

Repository Mirroring and Backup:

# Set up mirroring
git clone --mirror <source> <mirror>           # Create mirror
git remote add mirror <mirror-url>             # Add mirror remote
git config remote.mirror.mirror true           # Configure mirroring

# Backup strategies
git bundle create backup.bundle --all          # Bundle backup
tar czf repo-backup.tar.gz .git/               # Directory backup
rsync -av .git/ /backup/location/              # Incremental backup

Repository Migration:

# Migrate repository
git clone --bare <old-repo> <new-repo>         # Clone bare
git remote add old <old-repo>                  # Add old remote
git push --all new                             # Push everything
git push --tags new                            # Push tags

# Update remotes
git remote set-url origin <new-url>            # Update origin
git remote remove old                          # Remove old remote

Repository Analysis Tools:

# Repository analysis scripts
analyze_repo() {
    echo "=== Repository Analysis ==="

    # Size analysis
    echo "Repository size:"
    du -sh .git/
    du -sh .git/objects/
    du -sh .git/logs/

    # Object analysis
    echo "Object counts:"
    git count-objects -v

    # Reference analysis
    echo "Reference counts:"
    echo "Branches: $(git branch -a | wc -l)"
    echo "Tags: $(git tag | wc -l)"
    echo "Remotes: $(git remote | wc -l)"

    # History analysis
    echo "Commit statistics:"
    echo "Total commits: $(git rev-list --all --count)"
    echo "Authors: $(git shortlog -sn | wc -l)"
}

analyze_repo

Repository Best Practices:

Repository Organization:

Repository Structure Guidelines:
├── Keep .git/ clean and optimized
├── Use descriptive branch names
├── Regular maintenance (gc, repack)
├── Backup critical repositories
├── Document repository structure
└── Use consistent naming conventions

Maintenance Schedule:
├── Daily: git status, basic operations
├── Weekly: git gc, reflog cleanup
├── Monthly: Full backup, integrity checks
└── Quarterly: Major cleanup, migration review

Security Considerations:

Repository Security:
├── Protect .git/ directory permissions
├── Use signed commits for important work
├── Validate hooks before installation
├── Monitor repository access
├── Regular security audits
└── Backup encryption

Access Control:
├── SSH key management
├── HTTPS authentication
├── Repository permissions
├── Hook security
└── Audit logging

Performance Optimization:

Performance Tuning:
├── Regular garbage collection
├── Object packing optimization
├── Reference packing
├── Sparse checkout for large repos
├── Alternates for shared storage
└── SSD storage for better I/O

Monitoring:
├── Repository size trends
├── Operation performance
├── Disk space usage
├── Network transfer rates
└── User activity patterns

Caution

Direct manipulation of .git/ contents can corrupt repositories. Always use Git commands for modifications. Backup before major operations. Some files are critical for repository integrity.

Real-World Usage Examples:

Repository Health Monitoring:

#!/bin/bash
# Repository health monitoring

monitor_repo_health() {
    echo "=== Repository Health Report ==="
    echo "Generated: $(date)"
    echo ""

    # Basic checks
    if [ ! -d .git ]; then
        echo "ERROR: Not a Git repository"
        exit 1
    fi

    # Repository type
    if git config --get core.bare 2>/dev/null | grep -q true; then
        echo "Repository type: Bare"
    else
        echo "Repository type: Working directory"
    fi

    # Size information
    echo "Size information:"
    echo "  Total: $(du -sh .git/ | cut -f1)"
    echo "  Objects: $(du -sh .git/objects/ 2>/dev/null | cut -f1)"
    echo "  Refs: $(du -sh .git/refs/ 2>/dev/null | cut -f1)"
    echo "  Logs: $(du -sh .git/logs/ 2>/dev/null | cut -f1)"

    # Object statistics
    echo "Object statistics:"
    git count-objects -v 2>/dev/null | sed 's/^/  /'

    # Reference counts
    echo "Reference counts:"
    echo "  Branches: $(git branch 2>/dev/null | wc -l)"
    echo "  Remote branches: $(git branch -r 2>/dev/null | wc -l)"
    echo "  Tags: $(git tag 2>/dev/null | wc -l)"

    # Integrity check
    echo "Integrity check:"
    if git fsck --quiet 2>/dev/null; then
        echo "  ✓ Repository integrity OK"
    else
        echo "  ✗ Repository integrity issues found"
        echo "  Run 'git fsck' for details"
    fi

    # Configuration check
    echo "Configuration check:"
    if [ -f .git/config ]; then
        echo "  ✓ Config file exists"
    else
        echo "  ✗ Config file missing"
    fi

    # Hook check
    if [ -d .git/hooks ]; then
        hook_count=$(find .git/hooks -type f -executable | wc -l)
        echo "  Executable hooks: $hook_count"
    fi

    echo ""
    echo "Health check complete"
}

monitor_repo_health

Repository Migration Script:

# Repository migration with layout preservation
migrate_repository() {
    local source_repo="$1"
    local target_repo="$2"
    local migration_type="${3:-full}"

    echo "Migrating repository from $source_repo to $target_repo"
    echo "Migration type: $migration_type"

    # Validate source
    if [ ! -d "$source_repo" ]; then
        echo "Source repository not found: $source_repo"
        return 1
    fi

    # Create target directory
    mkdir -p "$target_repo"

    case "$migration_type" in
        "bare")
            # Bare repository migration
            echo "Creating bare repository..."
            git clone --bare "$source_repo" "$target_repo"

            # Preserve configuration
            if [ -f "$source_repo/.git/config" ]; then
                cp "$source_repo/.git/config" "$target_repo/config"
            fi
            ;;

        "mirror")
            # Mirror migration
            echo "Creating mirror..."
            git clone --mirror "$source_repo" "$target_repo"

            # Convert to bare if needed
            cd "$target_repo"
            git config core.bare true
            cd -
            ;;

        "full")
            # Full migration with working tree
            echo "Creating full repository..."
            git clone "$source_repo" "$target_repo"

            # Preserve additional files
            cp "$source_repo/.gitignore" "$target_repo/" 2>/dev/null || true
            cp "$source_repo/.gitattributes" "$target_repo/" 2>/dev/null || true
            ;;
    esac

    # Verify migration
    echo "Verifying migration..."
    if GIT_DIR="$target_repo" git fsck --quiet 2>/dev/null; then
        echo "✓ Migration successful"
    else
        echo "✗ Migration verification failed"
        return 1
    fi

    # Show statistics
    echo "Migration statistics:"
    echo "  Source objects: $(GIT_DIR="$source_repo/.git" git count-objects -v 2>/dev/null | grep 'count:' | cut -d: -f2)"
    echo "  Target objects: $(GIT_DIR="$target_repo" git count-objects -v 2>/dev/null | grep 'count:' | cut -d: -f2)"

    echo "Migration complete"
}

migrate_repository "/path/to/source" "/path/to/target" "bare"

Repository Cleanup Automation:

# Automated repository cleanup
automated_cleanup() {
    local cleanup_level="${1:-standard}"

    echo "Starting automated repository cleanup: $cleanup_level"

    # Backup current state
    backup_ref=$(git rev-parse HEAD)
    echo "Backup reference: $backup_ref"

    case "$cleanup_level" in
        "light")
            # Light cleanup
            git gc --quiet
            git reflog expire --expire=30.days --all
            ;;

        "standard")
            # Standard cleanup
            git gc --aggressive --quiet
            git repack -a -d --quiet
            git pack-refs --all
            git reflog expire --expire=90.days --all
            ;;

        "deep")
            # Deep cleanup
            git gc --aggressive --prune=now
            git repack -a -d --depth=250 --window=250
            git pack-refs --all
            git reflog expire --expire=1.year --all
            git clean -fd  # Remove untracked files
            ;;
    esac

    # Update statistics
    echo "Cleanup results:"
    echo "  Objects: $(git count-objects | cut -d' ' -f1) loose, $(git count-objects | cut -d' ' -f3) packs"
    echo "  Size: $(du -sh .git/ | cut -f1)"

    # Verify repository
    if git fsck --quiet; then
        echo "✓ Repository integrity verified"
    else
        echo "✗ Repository integrity issues - check backup: $backup_ref"
        git reset --hard "$backup_ref"  # Restore if needed
    fi

    echo "Cleanup complete"
}

automated_cleanup "standard"

Repository Auditing:

# Repository auditing and compliance
audit_repository() {
    echo "=== Repository Audit Report ==="
    echo "Audit date: $(date)"
    echo ""

    # Repository identification
    if [ -f .git/config ]; then
        repo_url=$(git config --get remote.origin.url 2>/dev/null || echo "No remote configured")
        echo "Repository URL: $repo_url"
    fi

    # Access control audit
    echo "Access control:"
    if [ -d .git/hooks ]; then
        hook_count=$(find .git/hooks -type f -executable | wc -l)
        echo "  Executable hooks: $hook_count"

        # Check for security hooks
        if [ -x .git/hooks/pre-receive ]; then
            echo "  ✓ Pre-receive hook present"
        else
            echo "  ⚠ No pre-receive hook"
        fi
    fi

    # Data integrity
    echo "Data integrity:"
    if git fsck --quiet 2>/dev/null; then
        echo "  ✓ Object integrity OK"
    else
        echo "  ✗ Object integrity issues"
    fi

    # Backup status
    echo "Backup status:"
    if [ -d "../backup" ] || [ -f "../backup.tar.gz" ]; then
        echo "  ✓ Backup appears to exist"
    else
        echo "  ⚠ No backup found"
    fi

    # Compliance checks
    echo "Compliance checks:"
    # Check for large files
    large_files=$(find .git/objects -type f -size +50M 2>/dev/null | wc -l)
    if [ "$large_files" -gt 0 ]; then
        echo "  ⚠ Large files detected: $large_files"
    fi

    # Check for sensitive data patterns
    sensitive_patterns=("password" "secret" "key" "token")
    for pattern in "${sensitive_patterns[@]}"; do
        matches=$(git log --all --grep="$pattern" --oneline | wc -l)
        if [ "$matches" -gt 0 ]; then
            echo "  ⚠ Potential sensitive data: $pattern ($matches matches)"
        fi
    done

    # Configuration audit
    echo "Configuration audit:"
    if git config --get receive.denyNonFastForwards | grep -q true; then
        echo "  ✓ Non-fast-forward protection enabled"
    else
        echo "  ⚠ Non-fast-forward protection disabled"
    fi

    echo ""
    echo "Audit complete"
}

audit_repository

Repository Template Creation:

# Create repository templates
create_repo_template() {
    local template_name="$1"
    local template_dir="$HOME/.git-templates/$template_name"

    echo "Creating repository template: $template_name"

    # Create template directory
    mkdir -p "$template_dir"

    # Initialize template
    cd "$template_dir"
    git init --bare

    # Set up standard hooks
    mkdir -p hooks
    cat > hooks/post-commit << 'EOF'
#!/bin/bash
# Template post-commit hook
echo "Commit created in $(basename "$GIT_DIR")"
EOF
    chmod +x hooks/post-commit

    # Set up standard config
    cat > config << EOF
[core]
    repositoryformatversion = 0
    filemode = true
    bare = true

[receive]
    denyNonFastForwards = true

[gc]
    auto = 1000
EOF

    # Create template description
    cat > description << EOF
Repository template: $template_name
Created: $(date)
Purpose: Standard repository setup
EOF

    # Set up standard structure
    mkdir -p info
    cat > info/exclude << EOF
# Template exclude patterns
*.tmp
*.log
.DS_Store
Thumbs.db
EOF

    cd -
    echo "Template created at: $template_dir"
    echo "Use with: git clone --template=$template_dir <repo>"
}

create_repo_template "standard-project"

Tip

Understand repository layout for effective Git administration. Use git init —bare for server repositories. Regular maintenance prevents performance issues. Always backup before major operations.

What are the main differences between bare and non-bare repositories?

Bare repositories have no working tree and are used for sharing (pushing/pulling), while non-bare repositories have a working tree for development. Bare repos end in .git and have core.bare=true.

Where are Git objects stored?

Objects are stored in .git/objects/ directory, either as loose files in subdirectories (first two chars of SHA-1) or in packed archives (.pack/.idx files) for efficiency.

What is the purpose of the refs/ directory?

refs/ contains reference files for branches (heads/), remote tracking branches (remotes/), tags (tags/), and other references like notes and replacements.

How does Git store configuration?

Repository configuration is stored in .git/config file. Global config in ~/.gitconfig, system config in /etc/gitconfig. Some settings also in info/ subdirectory.

What is the index and where is it stored?

The index (staging area) is stored in .git/index file. It contains file stat info, object IDs, and tracks staged changes for the next commit.

What are reflogs and where are they stored?

Reflogs track reference changes and are stored in .git/logs/ directory. They enable recovery from mistakes and provide reference history.

How do Git hooks work and where are they stored?

Hooks are executable scripts in .git/hooks/ directory. They run at specific points in Git operations and can modify behavior or enforce policies.

What is a packed-refs file?

packed-refs is a file that stores multiple references efficiently instead of individual files. It’s created by git pack-refs —all for performance.

How do alternates work in Git?

Alternates allow sharing object storage between repositories. .git/objects/info/alternates contains paths to other object stores to search.

What is the purpose of the info/ directory?

.git/info/ contains repository-specific information like global excludes, attributes, grafts, and sparse-checkout patterns that shouldn’t be shared.

How does Git handle worktrees?

Worktrees allow multiple working directories for the same repository. Information is stored in .git/worktrees/ with each worktree having its own HEAD and index.

What are the different ways to initialize a Git repository?

git init (working directory), git init —bare (bare), git clone (copy existing), git worktree add (add worktree to existing).

How can I check repository integrity?

Use git fsck to check object connectivity and integrity, git count-objects for statistics, and manual inspection of .git structure.

What happens during git gc?

git gc performs garbage collection: packs loose objects, expires reflogs, removes unreachable objects, and optimizes repository structure.

How do I migrate a repository to a new structure?

Use git filter-branch, git fast-export/git fast-import, or manual restructuring with git read-tree and update-ref for complex changes.

What are the security implications of repository layout?

Protect .git directory permissions, validate hooks, monitor access, encrypt backups, and be aware of information leakage through reflogs and object storage.

Applications of the git repository-layout command

1. Repository Administration: Understanding and managing Git repository structure
2. Troubleshooting: Diagnosing repository corruption and performance issues
3. Migration Planning: Planning repository moves and restructuring
4. Backup Strategy: Designing effective repository backup approaches
5. Security Auditing: Assessing repository security and access controls
6. Performance Tuning: Optimizing repository layout for better performance