Chapter 1. Introduction to deploying a Block Storage service custom back end

The Red Hat OpenStack Platform director installs and manages a complete, Enterprise-grade OpenStack deployment with minimal manual configuration. For more information about the director, see the Director Installation and Usage guide.

The Openstack environment that director creates is called the overcloud. The overcloud contains all the components that provide services to end users, including Block Storage. This document provides guidance about how to deploy a custom back end to the Block Storage service (cinder) on the overcloud. By default, the Block Storage service is installed on Controller nodes.

Prerequisites

  • You have already deployed the overcloud with the director.
  • The overcloud has a functioning Block Storage service.
  • You are familiar with Block Storage concepts and configuration. For more information about Block Storage, see Block Storage and Volumes in the Storage Guide.
Warning

This procedure has been tested successfully in limited use cases. Ensure that you test your planned deployment on a non-production environment first. If you have any questions, contact Red Hat support.

1.1. Understanding custom back ends

A custom back end is a storage server, appliance, or configuration that is not yet fully integrated into the Red Hat OpenStack Platform director. Supported Block Storage back ends are already integrated and pre-configured with built-in director files. For example, Red Hat Ceph and single-back end configurations of Dell EMC PS Series, Dell Storage Center, and NetApp appliances.

Some integrated storage appliances support only a single-instance back end. For example, with the pre-configured director files for Dell Storage Center, you can only deploy a single back end. If you want to deploy multiple back end instances of this appliance, you need a custom configuration.

Although you can manually configure the Block Storage service by directly editing the /etc/cinder/cinder.conf file on the node where the Block Storage service is located, the director overwrites your configuration when you run the openstack overcloud deploy command. For more information, see Chapter 3, Deploying the configured back ends. Deploy the Block Storage back end with the director to ensure that your settings persist through overcloud deployments and updates.

If your back end configuration is fully integrated you can edit and invoke the packaged environment files. However, for custom back ends, you must write your own environment file. This document includes the annotated /home/stack/templates/custom-env.yaml file that you can edit for your deployment. This sample file is suitable for configuring the Block Storage service to use two NetApp back ends. For more information about environment files, see Including environment files in an overcloud deployment in the Director Installation and Usage guide.

1.2. Requirements

The following additional prerequisite conditions must apply to your environment to configure custom Block Storage back ends:

  • If you are using third-party back end appliances, you have configured them as storage repositories.
  • You have deployed the overcloud with director with the instructions in Director Installation and Usage.
  • You have the username and password of an account with elevated privileges. You can use the same stack user account that you created to deploy the overcloud.
  • You have already planned the resulting configuration that you want for the Block Storage back end in /etc/cinder/cinder.conf.

1.3. Understanding the configuration process

Configuring the Block Storage service to use custom back ends involves the following steps: