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

Recovering from a disaster!


The following recipes will show how to fail over to the mirrored data on the backup cluster after the primary cluster ceph has encountered a disaster and how to failback once the ceph cluster has recovered. There are two methods for failover when dealing with a disaster:

  • Orderly: Failover after an orderly shutdown. This would be a proper shutdown of the cluster and demotion and promotion of the image.
  • Non-orderly: Failover after a non-orderly shutdown. This would be a complete loss of the primary cluster. In this case, the failback would require a resynchronizing of the image.

How to do it...

  1. How to properly failover after an orderly shutdown:
    • Stop all client's that are writing to the primary image
    • Demote the primary image located on the ceph cluster:
               # rbd mirror image demote data/image-1
    • Promote the non-primary image located on the backup cluster:
                # rbd-mirror image promote data/image-1
    • Validate image has become primary on the backup cluster...