du – estimate file space usage

du shows disk usage for files and directories. Use it to find what’s consuming space.

Synopsis

du [OPTIONS] [FILE...]

Common Options

Examples

Directory size (human-readable)

$ du -sh /var/log
2.4G    /var/log

Multiple directories

$ du -sh /home/* 
15G     /home/greys
8.2G    /home/admin
234M    /home/guest

All subdirectories

$ du -h /var/log
4.0K    /var/log/apt
1.2G    /var/log/journal
234M    /var/log/nginx
2.4G    /var/log

Limit depth

$ du -h --max-depth=1 /var
512M    /var/cache
2.4G    /var/log
4.0G    /var/lib
8.1G    /var

Sort by size (largest first)

$ du -sh /var/* | sort -rh
4.0G    /var/lib
2.4G    /var/log
512M    /var/cache

Find largest directories

$ du -h /home | sort -rh | head -10

Include files (not just directories)

$ du -ah /etc | sort -rh | head -20

Show grand total

$ du -shc /var/log /var/cache
2.4G    /var/log
512M    /var/cache
2.9G    total

Stay on one filesystem

$ du -shx /    # Won't cross into mounted drives

Common Patterns

Find what’s using space

$ du -h --max-depth=1 / 2>/dev/null | sort -rh | head -15

Top 10 largest directories in /home

$ du -sh /home/*/* 2>/dev/null | sort -rh | head -10

Exclude pattern

$ du -sh --exclude='*.log' /var

Tips

• Always use -h: Human-readable is essential
• Use ncdu: Interactive disk usage browser (better for exploration)
• Combine with sort: du -sh * | sort -rh
• Permission errors: Add 2>/dev/null to hide them
• Different from ls -l: du shows actual disk usage, ls shows file size

See Also

Related Commands

• df — Filesystem space usage
• ls — File sizes with -lh
• ncdu — Interactive disk usage viewer
• find — Find large files

Tutorials

• Basic Unix Commands