Dry Run & Testing

Dry Run Flags

Flag	Purpose
-n / --dry-run	Preview changes, don't execute
--itemize-changes	Show what would change and why
--stats	Show transfer statistics
-v	List files that would transfer
-i	Short for --itemize-changes

Common Patterns

# Basic dry run
rsync -avn src/ dest/

# Dry run with detailed changes
rsync -avn --itemize-changes src/ dest/

# Preview deletions
rsync -avn --delete src/ dest/

# Preview with statistics
rsync -avn --stats src/ dest/

# Test exclude patterns
rsync -avn --exclude='cache/' --exclude='*.log' src/ dest/

# Count what would transfer
rsync -avn src/ dest/ | wc -l

# Count what would be deleted
rsync -avn --delete src/ dest/ | grep "^deleting" | wc -l

# Save dry run to file for review
rsync -avn --itemize-changes src/ dest/ > /tmp/rsync-preview.txt

What Dry Run Doesn't Test

 Disk space on destination
 Network stability over full transfer
 File locks during long transfers
 Permission errors on write
 SSH timeout on large jobs

tip

Always dry-run before using --delete on production. Review the output carefully — especially lines starting with *deleting.