NerdTools

If your server isn't reporting metrics, here are some things to check.

Server shows as Offline

The server is marked offline if no report has been received in the last 5 minutes.

1. Check the agent is running: Look for the cron job in /etc/cron.d/nerdtools-agent
2. Check the log file: tail /var/log/nerdtools-agent.log for error messages
3. Run the agent manually: sudo /usr/local/bin/nerdtools-agent and watch for errors
4. Verify network access: The agent needs outbound HTTPS (port 443) to api.nerdtools.co.uk

"post failed" in the log

This usually means the agent couldn't reach the NerdTools API. Possible causes:

• Firewall blocking outbound HTTPS — Check your firewall rules
• DNS resolution failure — Verify the server can resolve api.nerdtools.co.uk
• Proxy required — If your server requires a proxy, curl needs to be configured to use it
• Invalid token — Double-check the token in /etc/nerdtools-agent.conf

Metrics look incorrect

• CPU always shows 0% on first run: This is normal. CPU usage is calculated from the delta between readings, so the first report has no baseline.
• Memory usage seems high: "Used" memory includes buffers and cache. This is expected behaviour on Linux. Only truly free memory is counted as free.
• Disk shows only root filesystem: The agent monitors / only. Other mount points are not currently tracked.

Agent not installed

If the installer failed:

1. Ensure you're running as root (sudo)
2. Check that curl is installed (which curl)
3. Verify the server can reach nerdtools.co.uk over HTTPS

Still having issues?

If you've tried the above and your server still isn't reporting, contact support with:

• The output of cat /etc/nerdtools-agent.conf (redact the token)
• The last 20 lines of /var/log/nerdtools-agent.log
• The output of curl -I https://api.nerdtools.co.uk/server-agent.php