Nagios

In our new VMware View and vCenter infrastructure, we're humming along, although in a matter of three weeks, we're nearly at capacity with our current hardware infrastructure (mostly in memory and disk space usage). As a result of our heavily loaded infrastructure, we've realized the criticality of setting up a monitoring system to monitor our servers and infrastructure components.

My previous experience has been limited to using Microsoft SCOM and I was not very impressed; granted I did not have the opportunity to really learn its ins and outs, I just know that we constantly had rogue alerts, false positives, and SCOM server problems (although these issues could very well be attributed to how it was set up, not the product itself).

Furthermore, our infrastructure is primarily Linux-based (RHEL Oracle server and ESX hosts), so why pay for a Microsoft tool designed to really monitor primarily Windows servers when we have the world of open-source available to us? Enter the picture Nagios, a free, open-source IT infrastructure monitor. Like many open source projects (think Red Hat, SLES, etc) the "core" is available for free and there is a pay-for commercial version. With our limited budget and no need for elaborate performance metrics and reports, we opted for Nagios Core. While it requires a decent amount of time to set up the service and host definitions, install the correct plugins, and configure the client monitors, we've been very pleased with it as a monitoring solution. It's pretty straightforward to set up and tweak, we can customize and adjust alert levels for individual hosts. And thanks to the engineers over at op5 (a monitor based heavily on Nagios core), we can monitor our VMware virtual datacenter with Nagios. While we're still waiting for our SMTP relay to be configured (the client wants ownership), so I can't opine on the email alert functionality, thus far we've been very pleased.