Many OpenStack services store their data in the /var/lib/kolla directory on the target nodes. If a service needs to store data, the /var/lib/kolla directory is created automatically when the service is deployed, and one or more subdirectories are created in /var/lib/kolla. The subdirectories are used as data volumes for the service's Docker containers. For example when you deploy the Nova service, the /var/lib/kolla/var/lib/nova/instances directory is created on compute nodes and this is used for ephemeral storage for instances (virtual machines).

The following services currently store data outside the /var/lib/kolla directory:

You must ensure that your target nodes have sufficient disk space to store OpenStack data, especially if you use ephemeral storage for instances.

You should create regular backups of your OpenStack data.