In VMware Integrated OpenStack 5.1, volume snapshots are taken as virtual machine templates. You can change the default to the copy-on-write (COW) format that was used in previous versions.


  1. Log in to the OpenStack Management Server as viouser.
  2. If your deployment is not using a custom.yml file, copy the template custom.yml file to the /opt/vmware/vio/custom directory.
    sudo mkdir -p /opt/vmware/vio/custom
    sudo cp /var/lib/vio/ansible/custom/custom.yml.sample /opt/vmware/vio/custom/custom.yml
  3. Open the /opt/vmware/vio/custom/custom.yml file in a text editor.
  4. Uncomment the cinder_vmware_snapshot_format parameter and set its value to COW.
  5. Deploy the updated configuration.
    sudo viocli deployment configure

    Deploying the configuration briefly interrupts OpenStack services.


New volume snapshots are taken in COW format.

What to do next

If you want to change the snapshot format back to the current default, set the value of the cinder_vmware_snapshot_format parameter to template.