How to Clean Up Your Root Directory in Ubuntu and Free Up Space

Running out of space on your Ubuntu root directory (/) can lead to system performance issues and even prevent updates or installations. If your / directory is nearing its capacity, it’s time for some cleanup. Follow these steps to efficiently free up space on your Ubuntu system.

1. Identify Large Files and Directories#

The first step is to find what’s taking up the most space.

sudo du -xh / | grep -P "^[0-9.]+G" | sort -hr | head -n 20

This command lists the top 20 largest files and directories. It gives you an idea of where to start.

2. Clear Package Cache#

Package managers often leave behind cached files. Clean them up with:

sudo apt-get clean
sudo apt-get autoremove

3. Remove Old Kernels#

Old kernels can occupy significant space. List installed kernels:

dpkg --list 'linux-image*'

Remove the old ones, ensuring not to remove the current kernel:

sudo apt-get remove --purge linux-image-<old-kernel-version>

4. Clear System Logs#

System logs can grow large over time. Limit them to the last few days:

sudo journalctl --vacuum-time=3d

5. Remove Unused Packages#

Identify and remove orphaned packages using deborphan:

sudo apt-get install deborphan
sudo deborphan | xargs sudo apt-get -y remove --purge

6. Check for Large Files#

Search for large files manually:

sudo find / -type f -size +100M -exec ls -lh {} \\;

Review and delete unnecessary files.

7. Clean Temporary Files#

Clear out temporary files:

sudo rm -rf /tmp/*
sudo rm -rf /var/tmp/*

8. Examine Disk Usage with ncdu#

Use ncdu to interactively check disk usage:

sudo apt-get install ncdu
sudo ncdu /

This tool helps you navigate and identify large directories.

9. Manual Inspection#

Check specific directories known for accumulating files:

sudo ls -lh /var/log
sudo ls -lh /var/cache

Manually remove unnecessary files.

10. Manage Snap Packages#

Snap packages can also take up space. List and clean up old revisions:

sudo snap list --all
sudo snap remove <old-snap-revision>