8 Managing Block Storage #

Log in to the Cloud Lifecycle Manager node.

Determine the host index numbers for each of your control plane nodes. This host index number will be used in a later step. They can be obtained by running this playbook:

cd ~/scratch/ansible/next/ardana/ansible
ansible-playbook -i hosts/verb_hosts cinder-show-volume-hosts.yml

Here is an example snippet showing the output of a single three node control plane, with the host index numbers in bold:

TASK: [_CND-CMN | show_volume_hosts | Show cinder Volume hosts index and hostname] ***
ok: [ardana-cp1-c1-m1] => (item=(0, 'ardana-cp1-c1-m1')) => {
    "item": [
        0,
        "ardana-cp1-c1-m1"
    ],
    "msg": "Index 0 Hostname ardana-cp1-c1-m1"
}
ok: [ardana-cp1-c1-m1] => (item=(1, 'ardana-cp1-c1-m2')) => {
    "item": [
        1,
        "ardana-cp1-c1-m2"
    ],
    "msg": "Index 1 Hostname ardana-cp1-c1-m2"
}
ok: [ardana-cp1-c1-m1] => (item=(2, 'ardana-cp1-c1-m3')) => {
    "item": [
        2,
        "ardana-cp1-c1-m3"
    ],
    "msg": "Index 2 Hostname ardana-cp1-c1-m3"
}

Locate the control plane fact file for the control plane you need to migrate the service from. It will be located in the following directory:

/etc/ansible/facts.d/

These fact files use the following naming convention:

cinder_volume_run_location_<control_plane_name>.fact

Edit the fact file to include the host index number of the control plane node you wish to migrate the cinder-volume services to. For example, if they currently reside on your first controller node, host index 0, and you wish to migrate them to your second controller, you would change the value in the fact file to 1.

If you are using data encryption on your Cloud Lifecycle Manager, ensure you have included the encryption key in your environment variables. For more information see Chapter 10, Encryption of Passwords and Sensitive Data.

export HOS_USER_PASSWORD_ENCRYPT_KEY=<encryption key>

After you have edited the control plane fact file, run the cinder volume migration playbook for the control plane nodes involved in the migration. At minimum this includes the one to start cinder-volume manager on and the one on which to stop it:

cd ~/scratch/ansible/next/ardana/ansible
ansible-playbook -i hosts/verb_hosts cinder-migrate-volume.yml --limit=<limit_pattern1,limit_pattern2>

Note

<limit_pattern> is the pattern used to limit the hosts that are selected to those within a specific control plane. For example, with the nodes in the snippet shown above, --limit=>ardana-cp1-c1-m1,ardana-cp1-c1-m2<

Even though the playbook summary reports no errors, you may disregard informational messages such as:

msg: Marking ardana_notify_cinder_restart_required to be cleared from the fact cache

Ensure that once your maintenance or other tasks are completed that you migrate the cinder-volume services back to their original node using these same steps.