Configure vCPU Distribution

The distribution and allocation of virtual CPUs in Cisco Catalyst 8000V can be configured based on the requirements of the network environment and the deployment needs. You can allocate a specific number of vCPUs to the Cisco Catalyst 8000V virtual machine, depending on the network's throughput and other requirements.

Allocating vCPUs maps the Cisco IOS XE processing threads in the Guest OS to vCPU threads. These threads are then assigned to physical cores. Allocating more vCPUs results in higher throughput and better performance.

Cisco offers several templates with pre-allocated vCPUs. You can select the template that best suits your needs, depending on the vCPU allocation for each template. See the sections in this chapter for details about the vCPU templates and guidance on choosing one for your network.

vCPU templates

To ease the allocation and distribution of vCPUs, Cisco offers several templates. These templates provide a predefined profile that determines how a VM allocates and distributes its vCPU resources. Based on the vCPU allocation defined for each of the templates, you can choose the template best suited for your needs. This list specifies the high-level categorization of the templates that Cisco Catalyst 8000V offers.

  • Service Plane Heavy: This template is recommended if you configure Cisco Catalyst 8000V as a service node for AppQoE. This profile is recommended when deploying the New Gen Firewall (NGFW) capabilities such as running Unified Threat Defense (UTD) containers on Cisco Catalyst 8000V. The minimum requirement for the Service Plane Heavy template is 8 vCPUs and 16 GB of memory, and this template includes containers running SNORT. This applies to both SD-WAN and autonomous mode deployments.

  • Control Plane Heavy: This template is recommended for use cases such as route reflector deployment and scaling FlexVPN to 10,000 deployments.

  • Data Plane Heavy: This is the default template for Cisco Catalyst 8000V. Use this template to achieve maximum forwarding performance.

For detailed allocation information for each template, see the tables in this chapter.

Guidelines to choose a template

This list provides a few guidelines before choosing a vCPU template.

  • Do not create a VM larger than the total number of physical cores of your host. For example, if you have a host system with six cores per NUMA node, it is recommended you size your virtual machines with no more than 6 vCPUs.

  • Using a Control Plane Extra heavy template, a service plane app can obtain 1.5 full cores for its operation in certain cases, for example, Wide Area Application Services (WAAS).

  • The Control Plane heavy template allocates an extra core to the Control Plane and Service Plane services compared to the Data Plane heavy template. The Control Plane receives one core, and the Service Plane receives another. If there is no Service Plane application, the Control Plane uses both the cores.

  • If the configuration output for the Template option reads 'None', the Data Plane heavy template is applied by default. However, this is not applicable for Cisco Catalyst 8000V instances running in the controller mode.

  • By default, the Cisco Catalyst 8000V core allocation favors a larger data plane for performance. If there is no Service Plane application, the Control Plane also utilizes the Service Plane's resources.

  • When using a Service Plane Heavy template, a Service Plane application such as Snort IPS can use up to 2 full cores for its operation.

Control Plane Extra Heavy template

This table specifies the vCPU distribution for the Control Plane Extra heavy template.

Table 1. vCPU distribution for Control Plane Extra Heavy template

Number of vCPUs

1

2

4

8

16

Control Plane

1/3

1/2

1 1/2

1 1/2

6

Service Plane

1/3

1/2

1 1/2

1 1/2

6

Data Plane

1/3

1

1

5

10

Control Plane Heavy template

This table shows the vCPU distribution for the Control Plane Heavy template.

Table 2. vCPU distribution for Control Plane Heavy template

Number of vCPUs

1

2

4

8

16

Control Plane

1/3

1/2

1

1

4

Service Plane

1/3

1/2

1

1

4

Data Plane

1/3

1

2

6

12

Data Plane Heavy template

This table shows the vCPU distribution for the Data Plane Heavy template.

Table 3. vCPU distribution for Data Plane Heavy template

Number of vCPUs

1

2

4

8

16

Control Plane

1/3

1/2

1/2

1/2

2

Service Plane

1/3

1/2

1/2

1/2

2

Data Plane

1/3

1

3

7

14

Data Plane Normal template

Data Plane Normal is a Cisco Catalyst 8000V resource profile which enables Cisco Catalyst 8000V to behave as it did prior to applying a vCPU distribution template. The Data Plane Normal template provides these features:

  • This template offers a balanced distribution of resources between the data, control, and service planes.

  • You can use the CLI to set this template for an instance. If you create a Cisco Catalyst 8000V VM with the Data Plane Heavy template for vCPU distribution as specified in the ovf-env.xml file, you can override these settings by using the CLI commands in the Data Plane Normal template.

Service Plane Heavy template

The table shows the vCPU distribution for the Service Plane Heavy template.

Table 4. vCPU distribution for Service Plane Heavy template

Number of vCPUs

1

2

4

8

16

Control Plane

1/3

1/2

1

2

8

Service Plane

1/3

1/2

1

2

8

Data Plane

1/3

1

2

4

8

Service Plane Medium template

The table shows the vCPU distribution for the Service Plane Medium template.

Table 5. vCPU distribution for Service Plane Medium template

Number of vCPUs

1

2

4

8

16

Control Plane

1/3

1/2

1

1

4

Service Plane

1/3

1/2

1

1

4

Data Plane

1/3

1

2

6

12

Manage vCPU distribution

Perform these steps to manage the vCPU distribution in Cisco Catalyst 8000V.

Procedure

Step 1

configure template platform resource template

Example:


Router# configure template
Enter configuration commands, one per line.  End with CNTL/Z.
Router(config)# platform resource ?
  control-plane-extra-heavy Use Control Plane Extra Heavy template
  control-plane-heavy   Use Control Plane Heavy template
  data-plane-heavy      Use Data Plane Heavy template
  data-plane-normal     Use Data Plane Normal template
  service-plane-heavy   Use Service Plane Heavy template
  service-plane-medium  Use Service Plane Medium template
Router(config)# platform resource service-plane-heavy

Allows you to select a resource template for Cisco Catalyst 8000V.

After entering the platform resource command, you must reboot the Cisco Catalyst 8000V instance to activate the template.

Step 2

show platform software cpu alloc

Example:


Router# show platform software cpu alloc
CPU alloc information:
Control plane cpu alloc: 0-1
Data plane cpu alloc: 2-3
Service plane cpu alloc: 0-1
Template used: CLI-service_plane_heavy

Determines which template is being used for vCPU distribution.

Note

 

The Control plane and the Service plane share cores 0 and 1.