WHM / cPanel Provides Munin for the Server Monitoring. It shows graphs for Disk, Exim, Mysql, Network, and Other Processes. I faced a issue on clients server where installation goes fine and Munin graphs are blank. I have made a short guide to trace the issue.
Restart Munin node and Watch for the logs for munin using :
/etc/init.d/munin-node restart
tail -f /var/log/munin/munin-node.log
Munin Errors :
2008/05/13-23:32:46 Server closing!
Process Backgrounded
2008/05/13-23:32:46 MyPackage (type Net::Server::Fork) starting! pid(25631)
Binding to TCP port 4949 on host *
Setting gid to “10 10”
Use of uninitialized value in eval {block} exit at /usr/sbin/munin-node line 452,line 8.
Munin uses port 4949, check the firewall and if possible disable the firewall during the troubleshooting.
munin 4949/tcp # Munin Graphing Framework
munin 4949/udp # Munin Graphing Framework
#telnet localhost 4949
Trying 127.0.0.1…
Connected to localhost.
Escape character is ‘^]’.
# munin node at [your server name]
Solution :
The above errors are when expected node hostname does not match the actual hostname of the server.
Ensure that the hostname entry is at the top and is correct in the /etc/hosts file.
Restart the munin node and use command to execute the munin.
/usr/bin/munin-cron –force-root
The munin should work fine now.