Disk Full

Full disk is one of the most frequent causes of malfunctions: sites not working, databases stop writing, error logs filling up. Here's how to fix it.

Quick check

df -h

If a line shows 100% or close, that partition is full. The main partition is usually mounted on /.

Find what's taking space

Largest folders in root

du -h / --max-depth=2 2>/dev/null | sort -rh | head -20

Enter the largest folder and analyze

du -h /var --max-depth=2 2>/dev/null | sort -rh | head -10

Find the largest files

find / -type f -size +100M 2>/dev/null | xargs ls -lh | sort -k5 -rh

Areas that fill up most often

1. System logs

# Check log size
du -sh /var/log/

# Delete old logs (older than 7 days)
journalctl --vacuum-time=7d

# Limit logs to max 500MB
journalctl --vacuum-size=500M

# See largest logs
ls -lhS /var/log/

2. Nginx / Apache logs

# Check size
du -sh /var/log/nginx/
du -sh /var/log/apache2/

# Empty a log (without deleting it)
> /var/log/nginx/access.log

# Configure automatic rotation
cat /etc/logrotate.d/nginx

3. Cache and packages

# Debian/Ubuntu
apt clean
apt autoremove -y

# CentOS
dnf clean all

4. /tmp files

du -sh /tmp/
rm -rf /tmp/*

5. MySQL logs

du -sh /var/log/mysql/

# MySQL binary logs (can become huge)
ls -lh /var/lib/mysql/mysql-bin.*

# In MySQL, purge old binary logs
mysql -u root -p -e "PURGE BINARY LOGS BEFORE DATE(NOW() - INTERVAL 3 DAY);"

6. Unused Docker images

# If you use Docker
docker system prune -a
docker volume prune

Emergency free space (quick)

# Combined quick cleanup
apt clean && apt autoremove -y
journalctl --vacuum-size=200M
rm -rf /tmp/*
find /var/log -name "*.gz" -delete
find /var/log -name "*.old" -delete

Prevention: configure logrotate

Make sure automatic log rotation is active:

# Check service
systemctl status logrotate

# Force manual rotation
logrotate -f /etc/logrotate.conf

Exhausted inodes

Sometimes df -h shows available space but disk is still "full". Check inodes:

df -i

If a partition is at 100% inode, find the folder with too many small files:

find / -xdev -printf '%h\n' 2>/dev/null | sort | uniq -c | sort -rn | head -10

Common causes: PHP sessions in /tmp, web cache files, email in spooler.

See the full guide: Disk Management

On this page