<b>Your dead box isn't out of RAM. It's out of inodes.</b>

<b>Your dead box isn't out of RAM. It's out of inodes.</b>

<code>df -h</code> says 40% free but everything's failing to write? Run <code>df -i</code>. A runaway log or a session dir with 2 million tiny files exhausts inodes long before disk space. The box is full of nothing.

— <code>df -i</code> to confirm
— <code>for d in /var/lib/php/sessions; do find $d -type f | wc -l; done</code>

Fix the source, then add <code>logrotate</code> with <code>maxsize 100M</code>. Most 'disk full' panics on cheap VPS are actually this. Try it tonight.