 <p>This is not really a programming question so it should be on superuser.</p> <p>Short answer -</p> <p>reboot the system.</p> <p>If the system comes back up, try:</p> <pre><code>find / -mtime -3 -size +100000 -exec ls -ls {} \; | sort -n </code></pre> <p>The largest newest files will be at the bottom of the list. If you can see that the file is not part of an app- a data file for example- remove it. You need at least 5% free space on /.</p> <p>Long term you must add more disk space, like double or triple what you have.</p>