The cluster CPU Usage charts monitor the CPU utilization of the hosts, resource pools, and virtual machines in the cluster. This chart displays the 10 child objects in the cluster with the most CPU usage.

This chart is located in the Resource Pools and Virtual Machines view of the Cluster Performance tab.

Table 1. Data Counters

Chart Label

Description

<host>, <resource pool>, or <virtual machine>

Amount of CPU actively used by the host, resource pool, or virtual machine in the cluster.

  • Counter: usagemhz

  • Stats Type: Rate

  • Unit: MegaHertz (MHz)

  • Rollup Type: Average (Minimum/Maximum)

  • Collection Level: 1 (4)

Chart Analysis

A short spike in CPU usage indicates that you are making the best use of cluster resources. However, if the value is constantly high, the CPU demanded is likely greater than the CPU capacity available. A high CPU usage value can lead to increased ready time and processor queuing of the virtual machines on the hosts in the cluster.

If performance is impacted, consider taking the following actions.

Table 2. CPU Performance Enhancement Advice

#

Resolution

1

Verify that VMware Tools is installed on each virtual machine.

2

If the cluster is not a DRS cluster, enable DRS. To enable DRS, perform the following tasks:

  1. Select the cluster, and click the Configure tab.

  2. Under Services, click vSphere DRS.

  3. click Edit.

    An Edit Cluster Settings dialog box opens.

  4. Click Turn ON vSphere DRS, and click OK.

3

If the cluster is a DRS cluster:

  • Increase the number of hosts, and migrate one or more virtual machines to the new host.

  • Check the aggressiveness threshold. If the value is low, increase the threshold. This might help avoid hot spots in the cluster.

4

Migrate one or more virtual machines to a new host.

5

Upgrade the physical CPUs or cores on each host in the cluster if necessary.

6

Enable CPU-saving features, such as TCP Segmentation Offload.

7

Replace software I/O with dedicated hardware, such as iSCSI HBAs or TCP Segmentation Offload NICs.