Red Hat Summit Red Hat SummitSupportConsoleDevelopersStart a trialContact

Chapter 8. Configuring an OVS-DPDK deployment

This section describes how to deploy DPDK with Open vSwitch (OVS-DPDK) within the Red Hat OpenStack Platform (RHOSP) environment. The overcloud usually consists of nodes in predefined roles such as Controller nodes, Compute nodes, and different storage node types. Each of these default roles contains a set of services defined in the core heat templates on the director node.

You must install and configure the undercloud before you can deploy the overcloud. For more information, see: Director Installation and Usage Guide.

Important

You must determine the best values for the OVS-DPDK parameters that you set in the network-environment.yaml file to optimize your RHOSP network for OVS-DPDK.

Note

Do not edit or change isolated_cores or other values in etc/tuned/cpu-partitioning-variables.conf that are modified by these director heat templates.

8.1. Deriving DPDK parameters with workflows
Copy link

This feature is available in this release as a Technology Preview, and therefore is not fully supported by Red Hat. It should only be used for testing, and should not be deployed in a production environment. For more information about Technology Preview features, see Scope of Coverage Details.

For an overview of the Mistral workflow for DPDK, see Section 7.2, “Overview of workflows and derived parameters”.

Prerequisites

You must have Bare Metal introspection, including hardware inspection_extras, enabled to generate the data retrieved by this workflow. Hardware inspection extras are enabled by default. See Inspecting the Hardware of Nodes.

Define the Workflows and Input Parameters for DPDK

The following lists the input parameters you can provide to the OVS-DPDK workflows:

num_phy_cores_per_numa_node_for_pmd
This input parameter specifies the required minimum number of cores for the NUMA node associated with the DPDK NIC. One physical core is assigned for the other NUMA nodes not associated with DPDK NIC. Ensure that this parameter is set to 1.
huge_page_allocation_percentage
This input parameter specifies the required percentage of total memory (excluding NovaReservedHostMemory) that can be configured as huge pages. The KernelArgs parameter is derived using the calculated huge pages based on the huge_page_allocation_percentage specified. Ensure that this parameter is set to 50.

The workflows use these input parameters and the bare-metal introspection details to calculate appropriate DPDK parameter values.

Perform the following steps to define the workflows and input parameters for DPDK:

  1. Copy the usr/share/openstack-tripleo-heat-templates/plan-samples/plan-environment-derived-params.yaml file to a local directory and set the input parameters to suit your environment. 

      workflow_parameters:
    tripleo.derive_params.v1.derive_parameters:
      # DPDK Parameters # DPDK Parameters # DPDK Parameters #
      # Specifies the minimum number of CPU physical cores to be allocated for DPDK
      # PMD threads. The actual allocation will be based on network config, if
      # the a DPDK port is associated with a numa node, then this configuration
      # will be used, else 1.
      num_phy_cores_per_numa_node_for_pmd: 1
      # Amount of memory to be configured as huge pages in percentage. Ouf the
      # total available memory (excluding the NovaReservedHostMemory), the
      # specified percentage of the remaining is configured as huge pages.
      huge_page_allocation_percentage: 50
    Copy to Clipboard Toggle word wrap

  2. Run the openstack overcloud deploy command with the following options:

    • The update-plan-only option
    • The role file and all environment files specific to your environment

    • The plan-environment-derived-parms.yaml file with the --plan-environment-file optional argument 

      $ openstack overcloud deploy --templates --update-plan-only \
-r /home/stack/roles_data.yaml \
-e /home/stack/<environment-file> \
... #repeat as necessary ...
-p /home/stack/plan-environment-derived-params.yaml
      Copy to Clipboard Toggle word wrap

The output of this command shows the derived results, which are also merged into the plan-environment.yaml file. 

Started Mistral Workflow tripleo.validations.v1.check_pre_deployment_validations. Execution ID: 55ba73f2-2ef4-4da1-94e9-eae2fdc35535
Waiting for messages on queue 472a4180-e91b-4f9e-bd4c-1fbdfbcf414f with no timeout.
Removing the current plan files
Uploading new plan files
Started Mistral Workflow tripleo.plan_management.v1.update_deployment_plan. Execution ID: 7fa995f3-7e0f-4c9e-9234-dd5292e8c722
Plan updated.
Processing templates in the directory /tmp/tripleoclient-SY6RcY/tripleo-heat-templates
Invoking workflow (tripleo.derive_params.v1.derive_parameters) specified in plan-environment file
Started Mistral Workflow tripleo.derive_params.v1.derive_parameters. Execution ID: 2d4572bf-4c5b-41f8-8981-c84a363dd95b
Workflow execution is completed. result:
ComputeOvsDpdkParameters:
 IsolCpusList: 1,2,3,4,5,6,7,9,10,17,18,19,20,21,22,23,11,12,13,14,15,25,26,27,28,29,30,31
 KernelArgs: default_hugepagesz=1GB hugepagesz=1G hugepages=32 iommu=pt intel_iommu=on
   isolcpus=1,2,3,4,5,6,7,9,10,17,18,19,20,21,22,23,11,12,13,14,15,25,26,27,28,29,30,31
 NovaReservedHostMemory: 4096
 NovaVcpuPinSet: 2,3,4,5,6,7,18,19,20,21,22,23,10,11,12,13,14,15,26,27,28,29,30,31
 OvsDpdkCoreList: 0,16,8,24
 OvsDpdkMemoryChannels: 4
 OvsDpdkSocketMemory: 1024,1024
 OvsPmdCoreList: 1,17,9,25
Copy to Clipboard Toggle word wrap
Note

You cannot derive the OvsDpdkMemoryChannels parameter from introspection details. In most cases, this value should be 4.

Deploy the overcloud with the derived parameters

Perform the following steps to deploy the overcloud with these derived parameters:

  1. Copy the derived parameters from the deploy command output to the network-environment.yaml file. 

      # DPDK compute node.
  ComputeOvsDpdkParameters:
    KernelArgs: default_hugepagesz=1GB hugepagesz=1G hugepages=32 iommu=pt intel_iommu=on
    TunedProfileName: "cpu-partitioning"
    IsolCpusList: "1,2,3,4,5,6,7,9,10,17,18,19,20,21,22,23,11,12,13,14,15,25,26,27,28,29,30,31"
    NovaVcpuPinSet: ['2,3,4,5,6,7,18,19,20,21,22,23,10,11,12,13,14,15,26,27,28,29,30,31']
    NovaReservedHostMemory: 4096
    OvsDpdkSocketMemory: "1024,1024"
    OvsDpdkMemoryChannels: "4"
    OvsDpdkCoreList: "0,16,8,24"
    OvsPmdCoreList: "1,17,9,25"
    Copy to Clipboard Toggle word wrap
    Note

    These parameters apply to the specific role, ComputeOvsDpdk. You can apply these parameters globally, but role-specific parameters overwrite global parameters.

  2. Deploy the overcloud using the role file and all environment files specific to your environment. For more information, see Deploying the Overcloud.
Note

In a cluster with Compute, ComputeOvsDpdk and ComputeSriov, the existing workflow to derive parameters applies the formula to the ComputeOvsDpdk role only.

8.2. OVS-DPDK topology
Copy link

With Red Hat OpenStack Platform, you can create custom deployment roles, using the composable roles feature, adding or removing services from each role. For more information on Composable Roles, see Composable Roles and Services.

This image shows an example Open vSwitch with Data Plane Development Kit (OVS-DPDK) topology with two bonded ports for the control plane and data plane:

OpenStack NFV Config Guide Topology 450694 0617 ECE OVS DPDK
View larger image
OpenStack NFV Config Guide Topology 450694 0617 ECE OVS DPDK

To configure OVS-DPDK, complete the following tasks:

  1. If you use composable roles, copy and modify the roles_data.yaml file to add the custom role for OVS-DPDK.
  2. Update the appropriate network-environment.yaml file to include parameters for kernel arguments and DPDK arguments.
  3. Update the compute.yaml file to include the bridge for DPDK interface parameters.
  4. Update the controller.yaml file to include the same bridge details for DPDK interface parameters.
  5. Run the overcloud_deploy.sh script to deploy the overcloud with the DPDK parameters.
Note

This guide provides examples for CPU assignments, memory allocation, and NIC configurations that can vary from your topology and use case. For more information about hardware and configuration options, see: Network Functions Virtualization Product Guide and Chapter 2, Hardware requirements.

Prerequisites

Note

Red Hat OpenStack Platform operates in OVS client mode for OVS-DPDK deployments.

8.3. Setting the MTU value for OVS-DPDK interfaces
Copy link

Red Hat OpenStack Platform supports jumbo frames for Open vSwitch with Data Plane Development Kit (OVS-DPDK). To set the maximum transmission unit (MTU) value for jumbo frames you must:

  • Set the global MTU value for networking in the network-environment.yaml file.
  • Set the physical DPDK port MTU value in the compute.yaml file. This value is also used by the vhost user interface.
  • Set the MTU value within any guest instances on the Compute node to ensure that you have a comparable MTU value from end to end in your configuration.
Note

VXLAN packets include an extra 50 bytes in the header. Calculate your MTU requirements based on these additional header bytes. For example, an MTU value of 9000 means the VXLAN tunnel MTU value is 8950 to account for these extra bytes.

Note

You do not need any special configuration for the physical NIC because the NIC is controlled by the DPDK PMD and has the same MTU value set by the compute.yaml file. You cannot set an MTU value larger than the maximum value supported by the physical NIC.

To set the MTU value for OVS-DPDK interfaces:

  1. Set the NeutronGlobalPhysnetMtu parameter in the network-environment.yaml file. 

    parameter_defaults:
  # MTU global configuration
  NeutronGlobalPhysnetMtu: 9000
    Copy to Clipboard Toggle word wrap
    Note

    Ensure that the NeutronDpdkSocketMemory value in the network-environment.yaml file is large enough to support jumbo frames. See Section 7.4.2, “Memory parameters” for details.

  2. Set the MTU value on the bridge to the Compute node in the controller.yaml file. 

      -
    type: ovs_bridge
    name: br-link0
    use_dhcp: false
    members:
      -
        type: interface
        name: nic3
        mtu: 9000
    Copy to Clipboard Toggle word wrap

  3. Set the MTU values for an OVS-DPDK bond in the compute.yaml file: 

    - type: ovs_user_bridge
  name: br-link0
  use_dhcp: false
  members:
    - type: ovs_dpdk_bond
      name: dpdkbond0
      mtu: 9000
      rx_queue: 2
      members:
        - type: ovs_dpdk_port
          name: dpdk0
          mtu: 9000
          members:
            - type: interface
              name: nic4
        - type: ovs_dpdk_port
          name: dpdk1
          mtu: 9000
          members:
            - type: interface
              name: nic5
    Copy to Clipboard Toggle word wrap

8.4. Configuring a firewall for security groups
Copy link

Data plane interfaces require a high degree of performance in a stateful firewall. To protect these interfaces, consider deploying a telco grade firewall as a virtual network function (VNF).

To configure the control plane interfaces, set the NeutronOVSFirewallDriver parameter to openvswitch. This configures Red Hat OpenStack Platform Networking to use the flow-based OVS firewall driver. This is set in the network-environment.yaml file under parameter_defaults.

Example: 

parameter_defaults:
  NeutronOVSFirewallDriver: openvswitch
Copy to Clipboard Toggle word wrap

It is important to disable OVS firewall driver for data plane interfaces, where applicable. This can be done with the openstack port set command.

Example: 

openstack port set --no-security-group  --disable-port-security ${PORT}
Copy to Clipboard Toggle word wrap

8.5. Setting multiqueue for OVS-DPDK interfaces
Copy link

To set set same number of queues for interfaces in Open vSwitch with Data Plane Development Kit (OVS-DPDK) on the Compute node, modify the compute.yaml file: 

- type: ovs_user_bridge
  name: br-link0
  use_dhcp: false
  members:
    - type: ovs_dpdk_bond
      name: dpdkbond0
      mtu: 9000
      rx_queue: 2
      members:
        - type: ovs_dpdk_port
          name: dpdk0
          mtu: 9000
          members:
            - type: interface
              name: nic4
        - type: ovs_dpdk_port
          name: dpdk1
          mtu: 9000
          members:
            - type: interface
              name: nic5
Copy to Clipboard Toggle word wrap

8.6. Deploying the overcloud
Copy link

  1. Ensure parameters for your DPDK compute role populate in network-environment.yaml. If necessary, copy these parameters from: derived OVS-DPDK. 

     # DPDK compute node.
  ComputeOvsDpdkParameters:
    KernelArgs: default_hugepagesz=1GB hugepagesz=1G hugepages=32 iommu=pt intel_iommu=on isolcpus=1-7,17-23,9-15,25-31
    TunedProfileName: "cpu-partitioning"
    IsolCpusList: "1-7,17-23,9-15,25-31"
    NovaVcpuPinSet: ['2-7,18-23,10-15,26-31']
    NovaReservedHostMemory: 4096
    OvsDpdkSocketMemory: "1024,1024"
    OvsDpdkMemoryChannels: "4"
    OvsDpdkCoreList: "0,16,8,24"
    OvsPmdCoreList: "1,17,9,25"
    Copy to Clipboard Toggle word wrap

  2. Deploy the overcloud using the openstack overcloud deploy command.

    • Include the role file and all environment files specific to your environment.

    • Apply the KernelArgs and TunedProfile parameters by including the host-config-and-reboot.yaml file from /usr/share/openstack-tripleo-heat-templates/environments to your deployment script: 

      TEMPLATES_HOME=”/usr/share/openstack-tripleo-heat-templates”
CUSTOM_TEMPLATES=”/home/stack/templates”

openstack overcloud deploy --templates \
-r ${CUSTOM_TEMPLATES}/roles_data.yaml \
-e ${TEMPLATES_HOME}/environments/host-config-and-reboot.yaml \
-e ${CUSTOM_TEMPLATES}/network-environment.yaml \
-e ${CUSTOM_TEMPLATES}/controller.yaml
-e ${CUSTOM_TEMPLATES}/computeovsdpdk.yaml \
...
      Copy to Clipboard Toggle word wrap

8.7. Known limitations
Copy link

There are limitations when configuring OVS-DPDK with Red Hat OpenStack Platform for the NFV use case:

  • Use Linux bonds for control plane networks. Ensure that the PCI devices in the Linux bond are on the same NUMA node for optimum performance. Red Hat does not support Neutron Linux bridge configuration.
  • Every instance running on the hosts with OVS-DPDK requires huge pages. If huge pages are not present in the guest, the interface appears but does not function.
  • With OVS-DPDK, there is a performance degradation of services that use tap devices, such as Distributed Virtual Routing (DVR). The resulting performance is not suitable for a production environment.
  • When using OVS-DPDK, all bridges on the same Compute node must be of type ovs_user_bridge. The director might accept the configuration, but Red Hat does not support mixing ovs_bridge and ovs_user_bridge on the same node.

After you configure Open vSwitch with Data Plane Development Kit (OVS-DPDK) for your Red Hat OpenStack Platform deployment with NFV, you can create a flavor and deploy an instance with the following steps:

  1. Create an aggregate group and add relevant hosts for OVS-DPDK. Define metadata, for example dpdk=true, that matches defined flavor metadata. 

     # openstack aggregate create dpdk_group
 # openstack aggregate add host dpdk_group [compute-host]
 # openstack aggregate set --property dpdk=true dpdk_group
    Copy to Clipboard Toggle word wrap
    Note

    Use host aggregates to separate CPU-pinned instances from unpinned instances. Instances without CPU pinning have different resourcing requirements of instances with CPU pinning.

  2. Create a flavor. 

    # openstack flavor create <flavor> --ram <MB> --disk <GB> --vcpus <#>
    Copy to Clipboard Toggle word wrap

  3. Set additional flavor properties. Note that the defined metadata, dpdk=true, matches the defined metadata in the DPDK aggregate. 

    # openstack flavor set <flavor> --property dpdk=true --property hw:cpu_policy=dedicated --property hw:mem_page_size=1GB --property hw:emulator_threads_policy=isolate
    Copy to Clipboard Toggle word wrap

    In this example, m1.medium_huge_4cpu is the flavor name and the remaining parameters set the other properties for the flavor.

    For details on the emulator threads policy for performance improvements, see: Configure Emulator Threads to run on a Dedicated Physical CPU.

  4. Create the network. 

    # openstack network create net1 --provider-physical-network tenant --provider-network-type vlan --provider-segment <VLAN-ID>
# openstack subnet create subnet1 --network net1 --subnet-range 192.0.2.0/24 --dhcp
    Copy to Clipboard Toggle word wrap

  5. Deploy an instance. 

    # openstack server create --flavor <flavor> --image <glance image> --nic net-id=<network ID>
    Copy to Clipboard Toggle word wrap

To use multi-queue with OVS-DPDK, set the hw_vif_multiqueue_enabled property on an image, before you set the hw.vif_multiqueue_enabled property on a flavor:

  1. Set the image properties. 

    # openstack image set --property hw_vif_multiqueue_enabled=true <image>
    Copy to Clipboard Toggle word wrap

  2. Set additional flavor properties. 

    # openstack flavor set --property hw:vif_multiqueue_enabled=true <flavor>
    Copy to Clipboard Toggle word wrap

8.9. Troubleshooting the configuration
Copy link

This section describes the steps to troubleshoot the Open vSwitch with Data Plane Development Kit (DPDK-OVS) configuration.

  1. Review the bridge configuration and confirm that the bridge was created with the datapath_type=netdev. 

    # ovs-vsctl list bridge br0
_uuid               : bdce0825-e263-4d15-b256-f01222df96f3
auto_attach         : []
controller          : []
datapath_id         : "00002608cebd154d"
datapath_type       : netdev
datapath_version    : "<built-in>"
external_ids        : {}
fail_mode           : []
flood_vlans         : []
flow_tables         : {}
ipfix               : []
mcast_snooping_enable: false
mirrors             : []
name                : "br0"
netflow             : []
other_config        : {}
ports               : [52725b91-de7f-41e7-bb49-3b7e50354138]
protocols           : []
rstp_enable         : false
rstp_status         : {}
sflow               : []
status              : {}
stp_enable          : false
    Copy to Clipboard Toggle word wrap

  2. Confirm that the docker container neutron_ovs_agent is configured to start automatically. 

    # docker inspect neutron_ovs_agent | grep -A1 RestartPolicy
            "RestartPolicy": {
                "Name": "always",
    Copy to Clipboard Toggle word wrap

  3. If the container has issues with starting, you can view any related messages. 

    # less /var/log/containers/neutron/openvswitch-agent.log
    Copy to Clipboard Toggle word wrap

  4. Confirm that the PMD CPU mask of the ovs-dpdk are pinned to the CPUs. In case of HT, use sibling CPUs.

    For example, observe CPU 4: 

    # cat /sys/devices/system/cpu/cpu4/topology/thread_siblings_list
4,20
    Copy to Clipboard Toggle word wrap

    Use CPU 4 and 20: 

    # ovs-vsctl set Open_vSwitch . other_config:pmd-cpu-mask=0x100010
    Copy to Clipboard Toggle word wrap

    Display their status: 

    # tuna -t ovs-vswitchd -CP
thread  ctxt_switches pid SCHED_ rtpri affinity voluntary nonvoluntary       cmd
3161	OTHER 	0    	6	765023      	614	ovs-vswitchd
3219   OTHER 	0    	6     	1        	0   	handler24
3220   OTHER 	0    	6     	1        	0   	handler21
3221   OTHER 	0    	6     	1        	0   	handler22
3222   OTHER 	0    	6     	1        	0   	handler23
3223   OTHER 	0    	6     	1        	0   	handler25
3224   OTHER 	0    	6     	1        	0   	handler26
3225   OTHER 	0    	6     	1        	0   	handler27
3226   OTHER 	0    	6     	1        	0   	handler28
3227   OTHER 	0    	6     	2        	0   	handler31
3228   OTHER 	0    	6     	2        	4   	handler30
3229   OTHER 	0    	6     	2        	5   	handler32
3230   OTHER 	0    	6	953538      	431   revalidator29
3231   OTHER 	0    	6   1424258      	976   revalidator33
3232   OTHER 	0    	6   1424693      	836   revalidator34
3233   OTHER 	0    	6	951678      	503   revalidator36
3234   OTHER 	0    	6   1425128      	498   revalidator35
*3235   OTHER 	0    	4	151123       	51       	pmd37*
*3236   OTHER 	0   	20	298967       	48       	pmd38*
3164   OTHER 	0    	6 	47575        	0  dpdk_watchdog3
3165   OTHER 	0    	6	237634        	0   vhost_thread1
3166   OTHER 	0    	6  	3665        	0       	urcu2
    Copy to Clipboard Toggle word wrap
Back to top
Red Hat logoGithubredditYoutubeTwitter

Learn

Try, buy, & sell

Communities

About Red Hat Documentation

We help Red Hat users innovate and achieve their goals with our products and services with content they can trust. Explore our recent updates.

Making open source more inclusive

Red Hat is committed to replacing problematic language in our code, documentation, and web properties. For more details, see the Red Hat Blog.

About Red Hat

We deliver hardened solutions that make it easier for enterprises to work across platforms and environments, from the core datacenter to the network edge.

Theme

© 2025 Red Hat