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

Topology


In this section, we'll describe commands to explore the logical layout of an example Ceph cluster. Before we go changing anything, we need to know exactly what we have first.

The 40,000 foot view

To visually see the overall topology of a Ceph cluster, run ceph osd tree. This will show us at once the hierarchy of CRUSH buckets, including the name of each bucket, the weight, whether it is marked up or down, a weight adjustment, and an advanced attribute of primary affinity. This cluster was provisioned initially with 3 racks each housing 4 hosts for a total of 12 OSD nodes. Each OSD node (also known as host, also known as server) in turn houses 24 OSD drives.

# ceph osd treeID  WEIGHT    TYPE NAME           UP/DOWN REWEIGHT PRIMARY-AFFINITY -1 974.89661 root default-14 330.76886     rack r1 -2  83.56099         host data001  0   3.48199             osd.0       up  1.00000          1.00000... 23   3.48199             osd.23      up  1.00000          1.00000 -3  80.08588         host data002...