The Memory (MB) chart displays memory data counters for resource pools or vApps.

This chart is located in the Home view of the resource pool or vApp Performance tab.

Note

These data counter definitions are for virtual machines. At the resource pool level, the values are collected and totaled. The counter values in the chart represent the aggregate amounts of the virtual machine data.The counters that appear in the chart depend on the collection level set for your vCenter Server.

Data Counters

Chart Label

Description

Active

Sum of the active guest physical memory of all powered on virtual machines in the resource pool.

Counter: active

Stats Type: Absolute

Unit: Megabytes (MB)

Rollup Type: Average (Minimum/Maximum)

Collection Level: 2 (4)

Balloon

Sum of the guest physical memory reclaimed by the balloon driver for all powered on virtual machines in the resource pool.

Counter: vmmemctl

Stats Type: Absolute

Unit: Megabytes (MB)

Rollup Type: Average (Minimum/Maximum)

Collection Level: 1 (4)

Consumed

Amount of physical memory consumed by the virtual machine for guest memory. Consumed memory does not include overhead memory. It includes shared memory and memory that might be reserved, but not actually used.

consumed memory = memory granted – memory saved due to memory sharing

Counter: consumed

Stats Type: Absolute

Unit: Megabytes (MB)

Rollup Type: Average (Minimum/Maximum)

Collection Level: 1 (4)

Granted

Sum of the guest physical memory granted for all powered on virtual machines. Granted memory is mapped to the host's machine memory.

Counter: granted

Stats Type: Absolute

Unit: Megabytes (MB)

Rollup Type: Average (Minimum/Maximum)

Collection Level: 2 (4)

Shared

Amount of guest physical memory shared with other virtual machines in the resource pool.

Swapped

Sum of the memory swapped by all powered on virtual machines in the resource pool.

Counter: swapused

Stats Type: Absolute

Unit: Megabytes (MB)

Rollup Type: Average (Minimum/Maximum)

Collection Level: 2 (4)

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.

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 the 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.