Boot a VM with CPU and memory pinning¶

This example demonstrates booting VM with CPU and memory pinning.

To boot VM with CPU and memory pining:

1. Create a new flavor with specific division of vCPUs and RAM between the NUMA nodes:

   . openrc admin admin
   nova flavor-create m1.numa_2 9992 1024 5 4
   

2. Add numa_nodes and other specific options to the flavor:

   nova flavor-key m1.numa_2 set hw:numa_nodes=2 hw:numa_cpus.0=0,2 \
        hw:numa_cpus.1=1,3 hw:numa_mem.0=324 hw:numa_mem.1=700
   nova flavor-show m1.numa_2 | grep extra
   

   Example of system response:

   | extra_specs  | {"hw:numa_cpus.0": "0,2", "hw:numa_cpus.1": "1,3", \
   "hw:numa_nodes": "2", "hw:numa_mem.1": "700", "hw:numa_mem.0": "324"} |
   

3. Create a new image or use an existing image.

   Note

   You need an Ubuntu image or the default Cirros image.

   To create a new Ubuntu image:

   glance --os-image-api-version 1 image-create --name ubuntu \
          --location https://cloud-images.ubuntu.com/trusty/current/\
          trusty-server-cloudimg-amd64-disk1.img \
          --disk-format qcow2 --container-format bare
   

4. To enable SSH connections:

   1. Add a new rule to the security group:

      nova secgroup-add-rule default tcp 22 22 0.0.0.0/0
      

   2. Create a new SSH key pair or use the existing key pair. To create a new ssh key pair, run:

      ssh-keygen
      

   3. Add the key pair to Nova:

      nova keypair-add --pub_key ~/.ssh/id_rsa.pub my_kp
      

5. Boot a new instance using the created flavor:

   nova boot --flavor m1.numa_2 --image ubuntu --key-name my_kp inst2
   

6. Verify if free memory has been changed after booting the VM:

   numactl -H
   

   Example of system response:

   available: 2 nodes (0-1)
   node 0 cpus: 0 1
   node 0 size: 3856 MB
   node 0 free: 293 MB           # was 718 MB
   node 1 cpus: 2 3
   node 1 size: 3937 MB
   node 1 free: 81 MB            # was 337 MB
   node distances:
   node   0   1
     0:  10  20
     1:  20  10
   

7. Retrieve the instance’s IP:

   nova show inst2 | awk '/network/ {print $5}'
   

   Example of system response:

   10.0.0.3
   

8. Connect to the VM using SSH:

   ssh ubuntu@10.0.0.3
   

9. Install numactl:

   sudo apt-get install numactl
   

10. Verify the NUMA topology on the VM:

    numactl -H
    

    Example of system response:

    available: 2 nodes (0-1)
    node 0 cpus: 0 2
    node 0 size: 303 MB
    node 0 free: 92 MB
    node 1 cpus: 1 3
    node 1 size: 689 MB
    node 1 free: 629 MB
    node distances:
    node   0   1
      0:  10  20
      1:  20  10
    

    You can see that the NUMA topology has two NUMA nodes. Total RAM size is about 1GB:

    • node-0 CPUs are 0 and 2
    • node-1 CPUs are 1 and 3, node-1 RAM is about 324 MB
    • node-2 RAM is about 700 as specified in the m1.numa_2 flavor