9.2. Adding a config drive to all instances

Procedure

1. Open your Compute environment file.

2. To always attach a config drive when launching an instance, set the following parameter to True:

   parameter_defaults:
     ComputeExtraConfig:
       nova::compute::force_config_drive: 'true'

3. Optional: To change the format of the config drive from the default value of iso9660 to vfat, add the config_drive_format parameter to your configuration:

   parameter_defaults:
     ComputeExtraConfig:
       nova::compute::force_config_drive: 'true'
       nova::compute::config_drive_format: vfat

4. Save the updates to your Compute environment file.

5. Add your Compute environment file to the stack with your other environment files and deploy the overcloud:

   (undercloud)$ openstack overcloud deploy --templates \
    -e [your environment files] \
    -e /home/stack/templates/<compute_environment_file>.yaml \

Verification

1. Create an instance:

   (overcloud)$ openstack server create --flavor m1.tiny \
    --image cirros test-config-drive-instance

2. Log in to the instance.

3. Mount the config drive:

   • If the instance OS uses udev:

     # mkdir -p /mnt/config
     # mount /dev/disk/by-label/config-2 /mnt/config

   • If the instance OS does not use udev, you need to first identify the block device that corresponds to the config drive:

     # blkid -t LABEL="config-2" -odevice
     /dev/vdb
     # mkdir -p /mnt/config
     # mount /dev/vdb /mnt/config

4. Inspect the files in the mounted config drive directory, mnt/config/openstack/{version}/, for your metadata.