Red Hat SummitChapter 1. Introduction
The Red Hat OpenStack Platform (RHOSP) director is a toolset for installing and managing a complete RHOSP environment. It is based primarily on the upstream TripleO (OpenStack-on-OpenStack) project. The primary objective of director is to fully orchestrate a functional, Enterprise-grade RHOSP deployment with minimal manual configuration. It helps to address many of the issues inherent in manually configuring individual OpenStack components.
The end-result RHOSP deployment provided by director is called the overcloud. The overcloud contains all the components that provide services to end users, including Block Storage. This document provides guidance on how to deploy custom back ends to the Block Storage service of the overcloud.
This document presumes existing knowledge of concepts relating to manual Block Storage configuration. In a test deployment of OpenStack (for example, through Packstack), configuring this service involves editing the /etc/cinder/cinder.conf of its host node . Most of the Block Storage settings in that file are documented in better detail elsewhere; this document describes how to apply those same settings to the overcloud to attach a custom back end.
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. Custom Back Ends
For the purposes of this document, a custom back end is defined as a storage server, appliance or configuration that has yet to be integrated fully into the Red Hat OpenStack Platform director. Some supported Block Storage back ends are already integrated into the director; this means that pre-configured director files are already provided. An integrated back end can be configured and deployed to the overcloud through these files. Examples of integrated back ends include Red Hat Ceph and single-back end configurations of Dell EMC PS Series, Dell Storage Center, and NetApp appliances.
Further, some storage appliances already integrated into director only support a single-instance back end. For example, the pre-configured director files for Dell Storage Center only support the deployment of a single back end. Deploying multiple back end instances of this appliance requires a custom configuration, as demonstrated in this document.
Although you can manually configure the Block Storage service by directly editing the /etc/cinder/cinder.conf file of its node, director overwrites your configuration when you run the openstack overcloud deploy command. For this reason, the recommended method for deploying a Block Storage back end is through the director, this ensures that your settings persist through overcloud deployments and updates.
If a back end configuration is already fully integrated, you can edit and invoke its packaged environment files. With custom back ends, however, you must write your own environment file. For more information, see Including Environment Files in Overcloud Creation in the Director Installation and Usage guide. This document includes an annotated sample that you can edit for your own deployment: /home/stack/templates/custom-env.yaml. This sample file is suitable for configuring the Block Storage service to use two NetApp back ends.
1.2. Requirements
Prerequisites
- In addition to prior knowledge about manually configuring Block Storage and the back end you want to deploy.
- If you are using third-party back end appliances, then they must already be properly configured as storage repositories.
- The overcloud has already been deployed through director. See the Director Installation and Usage guide.
-
You have the username and password of an account with elevated privileges. You can use the same account that you created to deploy the overcloud. See Creating the stack user, in the Director Installation and Usage guide. The
stackuser is created for this purpose. -
You have already mapped out the resulting configuration you want for the Block Storage back end in
/etc/cinder/cinder.conf.
