Book Image

Mastering Ceph - Second Edition

By : Nick Fisk
Book Image

Mastering Ceph - Second Edition

By: Nick Fisk

Overview of this book

Ceph is an open source distributed storage system that is scalable to Exabyte deployments. This second edition of Mastering Ceph takes you a step closer to becoming an expert on Ceph. You’ll get started by understanding the design goals and planning steps that should be undertaken to ensure successful deployments. In the next sections, you’ll be guided through setting up and deploying the Ceph cluster with the help of orchestration tools. This will allow you to witness Ceph’s scalability, erasure coding (data protective) mechanism, and automated data backup features on multiple servers. You’ll then discover more about the key areas of Ceph including BlueStore, erasure coding and cache tiering with the help of examples. Next, you’ll also learn some of the ways to export Ceph into non-native environments and understand some of the pitfalls that you may encounter. The book features a section on tuning that will take you through the process of optimizing both Ceph and its supporting infrastructure. You’ll also learn to develop applications, which use Librados and distributed computations with shared object classes. Toward the concluding chapters, you’ll learn to troubleshoot issues and handle various scenarios where Ceph is not likely to recover on its own. By the end of this book, you’ll be able to master storage management with Ceph and generate solutions for managing your infrastructure.
Table of Contents (18 chapters)
Free Chapter
1
Section 1: Planning And Deployment
6
Section 2: Operating and Tuning
13
Section 3: Troubleshooting and Recovery

Tiering modes

There are a number of tiering modes that determine the precise actions of how Ceph reacts to the contents of the HitSets. However, in most cases, the writeback mode will be used. The available modes for use in tiering are writeback, forward, read-forward, proxy, and read-proxy. The following sections provide brief descriptions of the available modes and how they act.

Writeback

In writeback mode, data is promoted to the top-level tier by both reads and writes depending on how frequently accessed the object is. Objects in the top-level tier can be modified, and dirty objects will be flushed to the pool at a later date. If an object needs to be read or written to in the bottom tier and the bottom pool supports it...