Jan 04

CentOS Observium Install Tips

Observium is a great tool for network monitoring, reporting and analysis. It’s community-supported version is free and very comprehensive, giving administrators deep visibility into their network links and devices including device-level, throughput, port information and more! I’ve successfully implemented it for switches, network devices, servers and storage arrays including NetApp products and been very happy with the results.

While the install guide at http://www.observium.org/wiki/RHEL_Installation is pretty comprehensive, there are a few gotchas that I’ve seen in a few installs that needed repair.

For one, graphs not populating- this is generally admin error when loading cron jobs. On the instructions, they advise to not use “crontab -e” to insert the jobs… This can easily be modified by cleaning up the syntax and removing the user command:

33 */6 * * * /opt/observium/discovery.php -h all >> /dev/null 2>&1
*/5 * * * * /opt/observium/discovery.php -h new >> /dev/null 2>&1
*/5 * * * * /opt/observium/poller-wrapper.py 1 >> /dev/null 2>&1

Once modified, modify crontab as the root user or by executing “sudo crontab -e -u root” as a user with sudo privileges.

Poller issues are also common, given that the default install uses only one by default. On most systems, this isn’t optimal and there is significant resources to allow more instances. To run more instances in parallel, modify the crontab entry for the poller, replacing the bold number to suit your environment:

*/5 * * * * /opt/observium/poller-wrapper.py 20 >> /dev/null 2>&1

If this causes IO issues, consider tuning it to your environment or using a RAM disk or faster storage.

MySQL tuning is also essential for larger environments, consider moving MySQL to a dedicated instance within the same LAN if possible or to a separate volume, again with faster storage such as an SSD, SAS drives and/or optimized RAID such as RAID 10 or RAID 6 depending on your system.

Do you have any tips or tricks to share? Feel free to comment with them! If you haven’t given Observium a try, visit the website at http://www.observium.org for a live demo, documentation and downloads.