Review: VMware's vCenter Operations Manager lightens the load
Monitoring virtual servers for availability, performance, health, and workload capacity has never been easy, but Operations Manager goes a long way toward that goalFollow @pvenezia
Clicking on the Efficiency score will give you a drill-down view into the reasoning behind the score, where you might see that perhaps 63 percent of the VMs running on a particular host are overspec'd. This drill-down will include a list of those VMs and recommendations on how to better utilize existing resources. You may see that several VMs that were assigned four vCPUs are really only using one or two, or a VM with 4GB of RAM never uses more than 1GB. Based on this data, you can then make adjustments to their resource allocations to free up resources for other VMs.
This level of granularity extends to every monitored object in Operations Manager. You can bring up a dashboard for a single VM; view its calculated Health, Risk, and Efficiency scores; and dig into the metrics that produced those scores. By selecting the Operations tab, you can view a series of graphs depicting the VM's key metrics and resource assignments, as well as an overall chart showing its health. Each chart has a bar above or next to it that shows the expected normal range for that metric, so you might see a current CPU workload of 10 percent, while the range bar shows that anything between 4 and 25 percent is normal for that VM. Anything outside of the calculated normal boundary can generate an alert.
It's important to note that the normal ranges are not merely calculated on an overall basis, but also balanced against day of week and time of day. A VM that pegs the CPU every night during a batch run does not necessarily generate an alarm during those times, because that's been observed to be normal operation. If the CPU pegs in the early afternoon, however, it may eclipse the calculated normal value, and an alert could then be generated.
The Operations view makes myriad data points available, and selecting All Metrics will bring up a display that allows you to specify multiple metrics across all resources, even including vCenter Server operations. The resulting graphs can be manipulated to change the date ranges for the display, and several other controls can be used to modify the graphical display itself, such as showing or hiding an axis or displaying a trend line. The scope of detail presented in this view is exemplary.
As with the Dashboard and Operations tabs, there is an Analysis tab for each monitored object. When looking at the cluster level, this shows various data sets that can be called up to reference the cluster. One example: "Which hosts have the most free capacity and the least stress?" Clicking on it brings up a heat map and host list that answers the question. Another example: "Which hosts have the most abnormal workload?"
These views are also available for different monitored objects, but differ in focus. For instance, when looking at a host, you might select "Which VMs have the highest CPU demand and contention?" This brings up another heat map and a list of VMs on that host, with their current CPU utilization. There are other views for data stores as well. This makes it very easy to get a solid look at the performance and capacity of the existing infrastructure, as well as to pinpoint problem areas.