The VM Contention dashboard is the primary dashboard for VM performance. It is designed for VMware administrators or architects. It can be used for both, monitoring, and troubleshooting. Once you determine that there is a performance issue, use the VM Utilization dashboard to see if the contention is caused by high utilization.

Design Considerations

This dashboard is used as part of your Standard Operating Procedure (SOP). It is designed for daily use, hence the views are set to show data for the last 24 hours. The dashboard provides performance metrics for virtual machines in the selected data center.

To view the common design considerations among all performance management dashboards, see the Performance Dashboards.

For understanding the performance concept of the selected counters and their thresholds, see the Performance Dashboards

How to Use the Dashboard

  • Select a data center from the data center table.
    • For a smaller environment, select vSphere World to see all the VMs from all the data centers.
      Note: The count of VMs includes the powered off VMs too. To exclude powered off VMs, modify the widget and select the running VM metric.
  • The two bar charts are automatically shown.
    • Use them together to get an insight about your CPU readiness and your Memory contention analysis. Analyze how the cluster serves the VMs. For each VM, it picks the worst metric in the last 24 hours. By default, vRealize Operations Cloud collects data every 5 minutes, so this is the highest value among 288 datapoints. Once it has the value from each VM, the bar charts puts each VM in the respective performance buckets. The threshold in the buckets considers best practices, hence they are color coded.
    • For any critical environment, expect that all the VMs are served well by the IaaS. You must see green on both distribution charts. For development purposes, you can tolerate a small amount of contention in both CPU and Memory.
  • VM Performance in selected Data Center.
    • Analyze by data center as performance problems tend to be isolated in a single physical environment. For example, a performance problem in country A typically does not cause a performance problem in country B.
    • The table is sorted by KPI Breach columns, directing your attention to the VMs that are not served well by the IaaS.
    • The table shows the hostnames known by Windows or Linux. This is the name that the application team or VM owner knows, as they might not be familiar with the VM name.
    • The rest of the columns show performance counters. Because the goal is proactive monitoring, the counters are the worst and not the average, during the monitoring period. Because the operations context here is performance, not capacity, the table considers the last 24 hours only. Daily use is encouraged as any activity older than 24 hours is considered irrelevant from a performance troubleshooting viewpoint.
    • The column KPI Breach counts the number of SLA breaches in any given 5 minutes. As a VM consumes four resources of IaaS (CPU, memory, disk, and network), the counter varies from 0–4, with 0 being the ideal. The value 4 indicates that all 4 IaaS services are not delivered. The same threshold is used regardless of class of service, as this is an internal KPI, not an external SLA. Your internal threshold should be more stringent, so that you have a reaction time.
  • Select a VM from the table.
    • All the health charts show the KPI of that VM.
    • The health charts display the last value, lowest value, and the peak value. Expect that the peak is within your threshold.

Points to Note

  • This dashboard uses Guest OS counters and VM counters appropriately. The two layers are distinct layers, and they each provide a unique visibility that the other layers might not give. For example, when the VMkernel de-schedules a VM as it has to process something else (for example, other VM, kernel interrupt). The Guest OS does not know the reason. In fact, it experiences frozen time for that particular vCPU running on the physical core and experiences time jumps when it is scheduled again.
  • Guest OS counters logically require VMware Tools.
  • The health chart is color coded. Change the settings if it does not suit your environment. If you are unsure of what suitable numbers to set for your environment, profile the metrics. The Guest OS Performance Profiling dashboard provides an example of how to profile metrics.
  • For a smaller environment with one or two data centers, change the filter from data center to cluster. Once you are list a cluster, you can then add the cluster performance (%) metric and sort them in an ascending order. This way the cluster that needs immediate attention is on the top.
  • If you have a screen real estate, group the VMs by cluster or by ESXi host. This way, you can quickly see if the problem is in a particular cluster or ESXi host.
  • Change the default timeline from one week to one day as and when required to suit your operations.
  • If you navigate a lot to the VM Utilization dashboard from this dashboard, add a connection using the dashboard to dashboard navigation feature. For more details, see Dashboard Navigation Details.