Book Image

Ceph: Designing and Implementing Scalable Storage Systems

By : Michael Hackett, Vikhyat Umrao, Karan Singh, Nick Fisk, Anthony D'Atri, Vaibhav Bhembre
Book Image

Ceph: Designing and Implementing Scalable Storage Systems

By: Michael Hackett, Vikhyat Umrao, Karan Singh, Nick Fisk, Anthony D'Atri, Vaibhav Bhembre

Overview of this book

This Learning Path takes you through the basics of Ceph all the way to gaining in-depth understanding of its advanced features. You’ll gather skills to plan, deploy, and manage your Ceph cluster. After an introduction to the Ceph architecture and its core projects, you’ll be able to set up a Ceph cluster and learn how to monitor its health, improve its performance, and troubleshoot any issues. By following the step-by-step approach of this Learning Path, you’ll learn how Ceph integrates with OpenStack, Glance, Manila, Swift, and Cinder. With knowledge of federated architecture and CephFS, you’ll use Calamari and VSM to monitor the Ceph environment. In the upcoming chapters, you’ll study the key areas of Ceph, including BlueStore, erasure coding, and cache tiering. More specifically, you’ll discover what they can do for your storage system. In the concluding chapters, you will develop applications that use Librados and distributed computations with shared object classes, and see how Ceph and its supporting infrastructure can be optimized. By the end of this Learning Path, you'll have the practical knowledge of operating Ceph in a production environment. This Learning Path includes content from the following Packt products: • Ceph Cookbook by Michael Hackett, Vikhyat Umrao and Karan Singh • Mastering Ceph by Nick Fisk • Learning Ceph, Second Edition by Anthony D'Atri, Vaibhav Bhembre and Karan Singh
Table of Contents (27 chapters)
Title Page
About Packt
Contributors
Preface
Index

Scaling down your Ceph cluster


One of the most important features of a storage system is its flexibility. A good storage solution should be flexible enough to support its expansion and reduction without causing any downtime to the services. Traditional storage systems have limited flexibility; the expansion and reduction of such systems is a tough job. Sometimes, you feel locked with storage capacity and that you cannot perform changes as per your needs.

Ceph is an absolutely flexible storage system that supports on-the-fly changes to storage capacity, whether expansion or reduction. In the last recipe, we learned how easy it is to scale out a Ceph cluster. In this recipe, we will scale down a Ceph cluster, without any impact on data accessibility, by removing ceph-node4 from the Ceph cluster.

How to do it...

Since removing an OSD node is not currently supported in ceph-ansible, let's follow the next set of steps to do this manually.

Removing the Ceph OSD

Before proceeding with the cluster size...