6.0.1

However, a consistently high memory usage value (94% or greater) indicates the host does not have the
memory resources required to meet the demand. If the memory balloon and swap values are not high,
performance is probably not affected. If the memory usage value is high, and the host 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 requires more memory resources.
If the host is not lacking memory resources, check the resource shares, reservation, and limit settings 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 machines.
If the host is lacking memory resources or you notice a degredation in performance, consider taking the
following actions.
Table 1‑63. 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 setting 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 hosts.
This chart is located in the Home view of the host Performance tab.
NOTE Guest physical memory refers to the virtual hardware memory presented to a virtual machine for its
guest operating system. Machine memory is the actual physical RAM in the host.
Not all counters are collected at collection level 1.
Table 1‑64. Data Counters
Chart Label Description
Active Sum of the active guest physical memory of all powered on virtual machines on the
host, plus memory used by basic VMKernel applications. Active memory is
estimated by the VMkernel and is based on the current workload of the host.
n
Counter: active
n
Stats Type: Absolute
n
Unit: Megabytes (MB)
n
Rollup Type: Average (Minimum/Maximum)
n
Collection Level: 2 (4)
Balloon Sum of the guest physical memory reclaimed by the balloon driver for all powered
on virtual machines on the host.
n
Counter: vmmemctl
n
Stats Type: Absolute
n
Unit: Megabytes (MB)
n
Rollup Type: Average (Minimum/Maximum)
n
Collection Level: 1 (4)
Chapter 1 Monitoring Inventory Objects with Performance Charts
VMware, Inc. 49