Book Image

Ceph Cookbook - Second Edition

By : Karan Singh, Hackett, Umrao
Book Image

Ceph Cookbook - Second Edition

By: Karan Singh, Hackett, Umrao

Overview of this book

Ceph is a unified distributed storage system designed for reliability and scalability. This technology has been transforming the software-defined storage industry and is evolving rapidly as a leader with its wide range of support for popular cloud platforms such as OpenStack, and CloudStack, and also for virtualized platforms. Ceph is backed by Red Hat and has been developed by community of developers which has gained immense traction in recent years. This book will guide you right from the basics of Ceph , such as creating blocks, object storage, and filesystem access, to advanced concepts such as cloud integration solutions. The book will also cover practical and easy to implement recipes on CephFS, RGW, and RBD with respect to the major stable release of Ceph Jewel. Towards the end of the book, recipes based on troubleshooting and best practices will help you get to grips with managing Ceph storage in a production environment. By the end of this book, you will have practical, hands-on experience of using Ceph efficiently for your storage requirements.
Table of Contents (15 chapters)

Creating a pool for cache tiering

To get the best out of the cache tiering feature of Ceph, you should use faster disks such as SSDs and make a fast cache pool on top of slower/regular pools made up of HDDs. In Chapter 9, Ceph Under the Hood, we covered the process of creating Ceph pools on specific OSDs by modifying the CRUSH map. To set up the cache tier in your environment, you need to first modify your crush map and create a ruleset for the SSD disk. Since we have already covered this in Chapter 9, Ceph Under the Hood, Creating Ceph Pools on Specific OSDs recipe we will use the same ruleset for SSD, which is based on osd.0, osd.3, and osd.6. As this is a test setup, and we do not have real SSDs, we will assume that OSDs zero, three, and six are SSDs and will create a cache pool on top of them, as illustrated in this diagram:

Let's check the CRUSH layout using the command...