Advanced Configuration

Advanced Configuration

For large installations using VXLAN encapsulation for Virtual Machine Manager (VMM) domains, you may need to make extra configurations.

You can configure the number of multicast groups to match the maximum number of endpoint groups (EPGs) for the host. You can also increase the maximum auxiliary memory for sockets and add extra kernel boot parameters to the compute or controller nodes.

Configure Multicast Groups and Increase Memory for Sockets

Procedure

Configure multicast groups and increase memory for sockets adding the following parameters to parameter_defaults in the deployment template:

Example:

parameter_defaults:  
  ControllerParameters:
      ExtraSysctlSettings:
         net.ipv4.igmp_max_memberships:
             value: 4096
         net.core.optmem_max:
             value: 1310720
   ComputeParameters:
      ExtraSysctlSettings:
         net.ipv4.igmp_max_memberships:
             value: 1024

The IGMP maximum memberships value should be greater than or equal to the number of Neutron networks that the host has Neutron ports on. For example, if a compute host has 100 instances, and each instance is on a different Neutron network, then you must set this number to at least 100. Controller hosts running the neutron-dhcp-agent must set this value to match the number of Neutron networks managed by that agent. This means that this number probably must be higher on controller hosts than compute hosts.

Add Extra Kernel Boot Parameters

You add extra kernel boot parameters to the compute or controller nodes by modifying the resource_registry and the parameter_defaults files.

Procedure

Step 1

Modify the resource_registry file.

Example:

resource_registry:
     OS::TripleO::Compute::PreNetworkConfig: /usr/share/openstack-tripleo-heat-templates/extraconfig/pre_network/host_config_and_reboot.yaml

Step 2

Modify the parameter_defaults file.

Example:

parameter_defaults:
    ComputeParameters:
        KernelArgs: "intel_iommu=on iommu=pt default_hugepagesz=1GB hugepagesz=1G hugepages=60"