9.1. Configuring Automatic Memory Management Policies

Note

Warning: This feature is experimental. The policies described in this section are subject to change.

Note

Note: This is a commercial feature. For information on how to purchase a Virtuozzo license and enable commercial features, please visit https://virtuozzo.com/.

Virtuozzo offers several techniques for automatically managing VM and container memory. The management is performed by the vcmmd daemon by means of policies described below. Setting the correct policy may provide performance and density benefits to your Virtuozzo installation.

The following policies are currently available:

  • NoOp, default. The simplest technique efficient in Virtuozzo installations with low memory usage.
  • WSSPolicy, combines the use of cgroups limits, swap, ballooning for virtual machines, and KSM. Best for Virtuozzo installations with high memory overcommit.
  • WFBPolicy, a compromise between the simplicity of NoOp and efficiency of WSSPolicy.

To switch to a policy, do the following:

  1. Set the required policy in /etc/vz/vcmmd.conf. For example, "Policy": "WSSPolicy".
  2. Restart vcmmd with

    # systemctl restart vcmmd

To check which policy is currently enabled, run

# vcmmdctl get-current-policy