Book Image

Ceph Cookbook

Book Image

Ceph Cookbook

Overview of this book

Ceph is a unified, distributed storage system designed for excellent performance, reliability, and scalability. This cutting-edge technology has been transforming the storage industry, and is evolving rapidly as a leader in software-defined storage space, extending full support to cloud platforms such as Openstack and Cloudstack, including virtualization platforms. It is the most popular storage backend for Openstack, public, and private clouds, so is the first choice for a storage solution. Ceph is backed by RedHat and is developed by a thriving open source community of individual developers as well as several companies across the globe. This book takes you from a basic knowledge of Ceph to an expert understanding of the most advanced features, walking you through building up a production-grade Ceph storage cluster and helping you develop all the skills you need to plan, deploy, and effectively manage your Ceph cluster. Beginning with the basics, you’ll create a Ceph cluster, followed by block, object, and file storage provisioning. Next, you’ll get a step-by-step tutorial on integrating it with OpenStack and building a Dropbox-like object storage solution. We’ll also take a look at federated architecture and CephFS, and you’ll dive into Calamari and VSM for monitoring the Ceph environment. You’ll develop expert knowledge on troubleshooting and benchmarking your Ceph storage cluster. Finally, you’ll get to grips with the best practices to operate Ceph in a production environment.
Table of Contents (18 chapters)
Ceph Cookbook
Credits
Foreword
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Understanding the CRUSH mechanism


When it comes to data storage and management, Ceph uses the CRUSH algorithm, which is the intelligent data distribution mechanism of Ceph. As we discussed in the last recipe, traditional storage systems use a central metadata/index table to know where the user's data is stored. Ceph, on the other hand, uses the CRUSH algorithm to deterministically compute where the data should be written to or read from. Instead of storing metadata, CRUSH computes metadata on demand, thus removing the need for a centralized server/gateway or broker. It empowers Ceph clients to compute metadata, also known as CRUSH lookup, and communicates with OSDs directly.

For a read-and-write operation to Ceph clusters, clients first contact a Ceph monitor and retrieve a copy of the cluster map, which is inclusive of 5 maps, namely the monitor, OSD, MDS, and CRUSH and PG maps; we will cover these maps later in this chapter. These cluster maps help clients know the state and configuration...