6.5.1

If the host has lile free memory available, or if you notice a degradation in performance, consider taking
the following actions.
Table 1‑16. Memory Performance Enhancement Advice
# Resolution
1 Verify that VMware Tools is installed on each virtual machine. The balloon driver is installed with VMware Tools
and is critical to performance.
2 Verify that the balloon driver is enabled. The VMkernel regularly reclaims unused virtual machine memory by
ballooning and swapping. Generally, it does not impact virtual machine performance.
3 Reduce the memory space on the virtual machine, and correct the cache size if it is too large. This frees up memory
for other virtual machines.
4 If the memory reservation of the virtual machine is set to a value much higher than its active memory, decrease the
reservation seing so that the VMkernel can reclaim the idle memory for other virtual machines on the host.
5 Migrate one or more virtual machines to a host in a DRS cluster.
6 Add physical memory to the host.
Memory Consumed
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 1‑17. 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
n
Counter: consumed
n
Stats Type: Absolute
n
Unit: MegaBytes (MB)
n
Rollup Type: Average (Minimum/Maximum)
n
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 1‑18. 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, it does not impact virtual machine performance.
vSphere Monitoring and Performance
20 VMware, Inc.