第1章 Introduction

Red Hat OpenStack Platform director creates a cloud environment called the overcloud. You can use director to configure extra features for an overcloud, including integration with Red Hat Ceph Storage (both Ceph Storage clusters created with the director or existing Ceph Storage clusters).

This guide includes instructions about how to integrate an existing Ceph Storage cluster with an overcloud. This means that director configures the overcloud to use the Ceph Storage cluster for storage needs. You manage and scale the cluster itself outside of the overcloud configuration.

This guide contains instructions for deploying a containerized Red Hat Ceph Storage cluster with your overcloud. Director uses Ansible playbooks provided through the ceph-ansible package to deploy a containerized Ceph cluster. The director also manages the configuration and scaling operations of the cluster.

For more information about containerized services in Red Hat OpenStack Platform (RHOSP), see Configuring a basic overcloud with the CLI tools in the Director Installation and Usage guide.

1.1. Introduction to Ceph Storage

Red Hat Ceph Storage is a distributed data object store designed to provide excellent performance, reliability, and scalability. Distributed object stores are the future of storage, because they accommodate unstructured data, and because clients can use modern object interfaces and legacy interfaces simultaneously. At the core of every Ceph deployment is the Ceph Storage cluster, which consists of several types of daemons, but primarily, these two:

Ceph OSD (Object Storage Daemon)
Ceph OSDs store data on behalf of Ceph clients. Additionally, Ceph OSDs utilize the CPU and memory of Ceph nodes to perform data replication, rebalancing, recovery, monitoring and reporting functions.
Ceph Monitor
A Ceph monitor maintains a master copy of the Ceph storage cluster map with the current state of the storage cluster.

For more information about Red Hat Ceph Storage, see the Red Hat Ceph Storage Architecture Guide.