The Memory Consumed chart displays memory usage for the 10 child objects in the cluster with the most consumed memory.

For resource pools and virtual machines in a cluster, this chart is located in the Resource Pools & Virtual Machines view of the cluster Performance tab. For hosts in a cluster, this chart is located in the Hosts view of the cluster Performance tab.

Table 1. Data Counters

Chart Label

Description

resource_pool, virtual_machine, or host

Amount of machine memory used by all resource pools and virtual machines in the cluster or by all hosts in the cluster, depending on the cluster view.

Consumed memory includes virtual machine memory, service console memory, and VMkernel memory.

consumed memory = total host memory - free host memory

  • Counter: consumed

  • Stats Type: Absolute

  • Unit: MegaBytes (MB)

  • Rollup Type: Average (Minimum/Maximum)

  • Collection Level: 1 (4)

Chart Analysis

Memory usage is not an indicator of performance problems. Memory can be high if a host is swapping or ballooning, which can result in virtual machine guest swapping. In such cases, check for other problems, such as CPU over-commitment or storage latencies.

If you have constantly high memory usage in a cluster, resource pool, or vApp, consider taking the following actions.

Table 2. Memory Performance Enhancement Advice

#

Resolution

1

Verify that VMware Tools is installed on each virtual machine.

2

Verify that the balloon driver is enabled. The balloon driver is installed with VMware Tools and is critical to performance. The VMkernel regularly reclaims unused virtual machine memory by ballooning and swapping. Generally, this does not impact virtual machine performance.

3

If the balloon value is high, check the resource shares, reservations, and limits for the virtual machines and resource pools on the hosts. Verify that the host's settings are adequate and not lower than those set for the virtual machine. If free memory is available on the hosts and the virtual machines are experiencing high swap or balloon memory, the virtual machine (or resource pool, if it belongs to one) has reached its resource limit. Check the maximum resource limit set on that host.

4

If the cluster is not a DRS cluster, enable DRS. Select the cluster in the object navigator, and click Manage > Settings > vSphere DRS > Edit > Turn ON vSphere DRS.

5

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.

6

Add more physical memory to one or more hosts.