6.5.1

Table 1‑112. 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, this 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 a 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 (MB)
The Memory (MB) chart displays memory data counters for virtual machines.
This chart is located in the Home view of the virtual machine Performance tab. It appears only at collection
levels 2, 3, and 4.
In the following descriptions, the guest physical memory refers to the virtual-hardware memory presented
to a virtual machine for its guest operating system. Machine memory is actual physical RAM in the host.
Note that not all counters are collected at collection level 1.
Table 1‑113. Data Counters
Chart Label Description
Active Amount of guest physical memory in use by the virtual machine.
Active memory is estimated by VMkernel statistical sampling and represents the actual
amount of memory the virtual machine needs. The value is based on the current workload
of the virtual machine.
n
Counter: active
n
Stats Type: Absolute
n
Unit: Megabytes (MB)
n
Rollup Type: Average (Minimum/Maximum)
n
Collection Level: 2 (4)
Balloon Amount of guest physical memory reclaimed from the virtual machine by the balloon
driver.
n
Counter: vmmemctl
n
Stats Type: Absolute
n
Unit: Megabytes (MB)
n
Rollup Type: Average (Minimum/Maximum)
n
Collection Level: 1 (4)
Balloon Target Desired amount of virtual machine balloon memory.
Balloon target memory is estimated by the VMkernel.
If the balloon target amount is greater than the balloon amount, the VMkernel inates the
balloon amount, which reclaims more virtual machine memory. If the balloon target
amount is less than the balloon amount, the VMkernel deates the balloon, which allows
the virtual machine to reallocate memory when needed.
n
Counter: vmmemctltarget
n
Stats Type: Absolute
n
Unit: Megabytes (MB)
n
Rollup Type: Average (Minimum/Maximum)
n
Collection Level: 2 (4)
vSphere Monitoring and Performance
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