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

Working with RBD clones


Ceph supports a very nice feature for creating Copy-On-Write (COW) clones from RBD snapshots. This is also known as snapshot layering in Ceph. Layering allows clients to create multiple instant clones of Ceph RBD. This feature is extremely useful for cloud and virtualization platforms such as OpenStack, CloudStack, Qemu/KVM, and so on. These platforms usually protect Ceph RBD images containing an OS/VM image in the form of a snapshot. Later, this snapshot is cloned multiple times to spawn new virtual machines/instances. Snapshots are read-only, but COW clones are fully writable; this feature of Ceph provides a greater level of flexibility and is extremely useful in cloud platforms. In the later chapters, we will discover more on COW clones for spawning OpenStack instances:

Every cloned image (child image) stores references of its parent snapshot to read image data. Hence, the parent snapshot should be protected before it can be used for cloning. At the time of data...