Monitoring Performance Metrics for VMs, Hosts and Clusters

Using vCommander, you can analyze how a VM, host or cluster is performing and what issues may be affecting its performance. Performance metrics are retrieved from the cloud provider.

In this topic:

About performance metrics in vCommander

vCommander monitors CPU, memory, disk and network usage over the last seven days. The average number is calculated by averaging the resource usage over the last seven days. vCommander also collects information about the maximum, or peak, resource usage, over the last seven days.

The last seven days of performance information is retrieved when a managed system is added to vCommander. SCVMM is the exception to this rule. For SCVMM, because historical performance data can't be retrieved from the managed system, vCommander waits to obtain seven days' worth of performance data from SCVMM before generating a performance summary.

VM performance metrics are updated automatically by vCommander every night. You can also manually update performance information for individual VMs.

GCP prerequisite: To allow vCommander to obtain metrics data for GCP VMs, the service account used to add GCP managed system must have at least the Monitoring Viewer role. To learn more, see Grant permissions to the vCommander service account.

Important: Memory usage monitoring requires additional configuration for public cloud instances. See:

Viewing a weekly VM performance summary

Access through:

Views menu > Operational or Deployed > Performance Summary tab

Available to:

View performance metrics: All Access Rights Levels

Update performance metrics: All Operator Levels and Higher

Use a VM's Performance Summary tab to view a summary of the last seven days of VM performance data. VM performance metrics are updated automatically by vCommander every night.

To update the performance summary information for a VM, so that it includes the most recent performance data:

  • select the VM in the tree, right-click and choose Performance > Update Performance

    OR

  • select the VM in the tree, select the Performance Summary tab, and click Update Performance in the upper-right corner

See also Managing Host and Cluster Capacity.

Here's the performance summary for an Amazon EC2 instance:

vm-perf-sum-aws

Performance metrics

Memory usage monitoring requires additional configuration for public cloud instances.

Metric

Description

Available for

CPU Usage (%)

Amount of actively used virtual CPU, as a percentage of total available CPU.

AWS, Azure, GCP, SCVMM, vCenter

CPU Usage (MHz)

Amount of actively used virtual CPU. This is the host's view of the CPU usage, not the guest operating system view.

vCenter

CPU Ready (%)

Percentage of time that the VM was ready, but couldn't be scheduled to run on the physical CPU. CPU ready time is dependent on the number of VMs on the host and their CPU loads.

vCenter

Memory Usage (%)

Percentage of allocated memory.

Note for SCVMM: Memory performance information is unavailable for VMs configured with static memory, because SCVMM always represents the memory usage as 100%.

AWS, Azure, GCP, SCVMM, vCenter

Memory Consumed (MB)

Amount of physical memory consumed by the VM.

Notes:

  • For private cloud, consumed memory doesn't include overhead memory. It includes shared memory and memory that might be reserved, but not actually used.
  • For public cloud Linux instances, the consumed memory is the "user" memory and doesn't include other categories such as buffer and cached memory.
  • For GCP Windows instances, consumed memory is calculated using (Total Memory * Usage Percentage).
  • For SCVMM, memory performance information is unavailable for VMs configured with static memory, because SCVMM always represents the memory usage as 100%.

AWS, Azure, GCP, SCVMM, vCenter

Memory Overhead (MB)

Amount of machine memory used by the VM kernel to run the VM.

vCenter

Memory Ballooning (MB)

Amount of guest physical memory that is currently reclaimed from the VM through ballooning. This is the amount of guest physical memory that has been allocated and pinned by the balloon driver.

vCenter

Disk Usage (MB/s)

Aggregated disk I/O rate.

Notes:

  • For public cloud, disk metrics are an aggregate of metrics for all disks on the VM. However, vCommander doesn't display Disk Usage for AWS instance store-backed volumes, and for Azure, disk metrics are retrieved only for OS disks.
  • For vCenter and SCVMM hosts, this metric includes the rates for all VMs running on the host during the collection interval. Not available for NFS.

AWS, Azure, GCP, SCVMM, vCenter

Disk Max Latency (ms)

Highest latency value for any operation executed by the VM. Latency measures the time taken to process a SCSI command issued by the guest OS to the VM.

vCenter

Disk Swap In (MB)

Rate at which memory is swapped from disk into active memory during the interval.

vCenter

Disk Swap Out (MB)

Rate at which memory is swapped from active memory to disk during the interval. This counter is generally more useful than the swap-in counter to determine whether the VM is running slowly due to swapping, especially when looking at real-time statistics.

vCenter

Disk IOPS

Sum of disk read and write IOPS.

For Azure, disk metrics are retrieved only for OS disks. This value is a sum of Disk Read Operations/Sec and Disk Write Operations/Sec.

For GCP, this value is a sum of compute.googleapis.com/instance/disk/read_ops_count and compute.googleapis.com/instance/disk/write_ops_count.

Azure, GCP

Network Usage (MB/s)

Sum of data transmitted and received across all virtual NIC instances connected to the VM.

AWS, Azure, GCP, SCVMM, vCenter

Analyzing the performance of vCenter VMs, hosts and clusters through charts

Access through:

Views menu > Operational or Deployed > Performance Charts tab

Available to:

View performance metrics: All Access Rights Levels

Update performance metrics: All Operator Levels and Higher

The Performance Charts tab for each VM, host and cluster displays the same performance charts that are displayed in VMware vSphere. Therefore, the charts you see are dependent on whether real-time graphs have been enabled in vSphere.

The performance charts are loaded the first time you click the Performance Charts tab for the selected VM, host or cluster, and they default to the time interval of one hour.

To see the performance over different periods of time, select from the Time Range drop-down menu as required (all performance charts are updated to display the same time periods).

Refresh the display at any time to receive the latest update from VMware.

For more information about these performance charts, refer to your VMware documentation.