Book Image

Ceph Cookbook - Second Edition

By : Vikhyat Umrao, Karan Singh, Michael Hackett
Book Image

Ceph Cookbook - Second Edition

By: Vikhyat Umrao, Karan Singh, Michael Hackett

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)

CRUSH map internals

To know what is inside a CRUSH map, and for easy editing, we need to extract and decompile it to convert it into a human-readable form. The following diagram illustrates this process:

The change to the Ceph cluster by the CRUSH map is dynamic, that is, once the new CRUSH map is injected into the Ceph cluster, all the changes will come into effect immediately, on the fly.

How to do it...

We will now take a look at the CRUSH map of our Ceph cluster:

  1. Extract the CRUSH map from any of the monitor nodes:
        # ceph osd getcrushmap -o crushmap_compiled_file
  1. Once you have the CRUSH map, decompile it to convert it into a human-readable/editable form:
        # crushtool -d crushmap_compiled_file 
...