6.7

Memory (%)
The Memory (%) chart monitors virtual machine memory usage.
This chart is located in the Home view of the virtual machine Performance tab.
Virtual Machine Counters
Note Guest physical memory refers to the virtual hardware memory presented to a virtual machine for its
guest operating system.
Table 1‑109. Data Counters
Chart Label Description
Usage Amount of guest physical memory currently in use on the virtual machine.
n
Counter: usage
n
Stats Type: Absolute
n
Unit: Percentage (%)
n
Rollup Type: Average (Minimum/Maximum)
n
Collection Level: 1 (4)
Chart Analysis
A virtual machine's memory size must be slightly larger than the average guest memory usage. This
enables the host to accommodate workload spikes without swapping memory among guests. Increasing
the virtual machine memory size results in more overhead memory usage.
If sufficient swap space is available, a high balloon value does not cause performance problems.
However, if the swapin and swapout values for the host are large, the host is probably lacking the amount
of memory required to meet the demand.
If a virtual machine has high ballooning or swapping, check the amount of free physical memory on the
host. A free memory value of 6% or less indicates that the host cannot meet the memory requirements.
This leads to memory reclamation, which might degrade performance. If the active memory size is the
same as the granted memory size, demand for memory is greater than the memory resources available. If
the active memory is consistently low, the memory size might be too large.
If the host has enough free memory, check the resource shares, reservation, and limit of the virtual
machines and resource pools on the host. Verify that the host settings are adequate and not lower than
those set for the virtual machine.
If little free memory is available, or if you notice degradation in performance, consider taking the following
actions.
vSphere Monitoring and Performance
VMware, Inc. 87