What This Book Covers
Chapter 1, Ceph - Introduction and Beyond, covers an introduction to Ceph, gradually moving toward RAID and its challenges, and a Ceph architectural overview. Finally, we will go through Ceph installation and configuration.
Chapter 2, Working with Ceph Block Device, covers an introduction to the Ceph Block Device and provisioning of the Ceph block device. We will also go through RBD snapshots and clones, as well as implementing a disaster-recovery solution with RBD mirroring.
Chapter 3, Working with Ceph and Openstack, covers configuring Openstack clients for use with Ceph, as well as storage options for OpenStack using cinder, glance, and nova.
Chapter 4, Working with Ceph Object Storage, covers a deep dive into Ceph object storage, including RGW setup and configuration, S3, and OpenStack Swift access. Finally, we will set up RGW with the Hadoop S3A plugin.
Chapter 5, Working with Ceph Object Storage Multi-Site v2, helps you to deep dive into the new Multi-site v2, while configuring two Ceph clusters to mirror objects between them in an object disaster recovery solution.
Chapter 6, Working with the Ceph Filesystem, covers an introduction to CephFS, deploying and accessing MDS and CephFS via kerenel, FUSE, and NFS-Ganesha.
Chapter 7, Operating and Managing a Ceph Cluster, covers Ceph service management with systemd, and scaling up and scaling down a Ceph cluster. This chapter also includes failed disk replacement and upgrading Ceph infrastructures.
Chapter 8, Ceph under the Hood, explores the Ceph CRUSH map, understanding the internals of the CRUSH map and CRUSH tunables, followed by Ceph authentication and authorization. This chapter also covers dynamic cluster management and understanding Ceph PG. Finally, we create the specifics required for specific hardware.
Chapter 9, The Virtual Storage Manager for Ceph, speaks about Virtual Storage Manager (VSM), covering it’s introduction and architecture. We will also go through the deployment of VSM and then the creation of a Ceph cluster, using VSM to manage it.
Chapter 10, More on Ceph, covers Ceph benchmarking, Ceph troubleshooting using admin socket, API, and the ceph-objectstore tool. This chapter also covers the deployment of Ceph using Ansible and Ceph memory profiling. Furthermore, it covers health checking your Ceph cluster using Ceph Medic and the new experimental backend Ceph BlueStore.
Chapter 11, Deploying Ceph, is a no-nonsense step-by-step instructional chapter on how to set up a Ceph cluster. This chapter covers the ceph-deploy tool for testing and goes onto covering Ansible. A section on change management is also included, and it explains how this is essential for the stability of large Ceph clusters.
Chapter 12, BlueStore, explains that Ceph has to be able to provide atomic operations around data and metadata and how filestore was built to provide these guarantees on top of standard filesystems. We will also cover the problems around this approach. The chapter then introduces BlueStore and explains how it works and the problems that it solves. This will include the components and how they interact with different types of storage devices. We will also have an overview of key-value stores, including RocksDB, which is used by BlueStore. Some of the BlueStore settings and how they interact with different hardware configurations will be discussed.
Chapter 13, Erasure Coding for Better Storage Efficiency, covers how erasure coding works and how it's implemented in Ceph, including explanations of RADOS pool parameters and erasure coding profiles. A reference to the changes in the Kraken release will highlight the possibility of append-overwrites to erasure pools, which will allow RBDs to directly function on erasure-coded pools. Performance considerations will also be explained. This will include references to BlueStore, as it is required for sufficient performance. Finally, we have step-by-step instructions on actually setting up erasure coding on a pool, which can be used as a mechanical reference for sysadmins.
Chapter 14, Developing with Librados, explains how Librados is used to build applications that can interact directly with a Ceph cluster. It then moves onto several different examples of using Librados in different languages to give you an idea of how it can be used, including atomic transactions.
Chapter 15, Distributed Computation with Ceph RADOS Classes, discusses the benefits of moving processing directly into the OSD to effectively perform distributed computing. It then covers how to get started with RADOS classes by building simple ones with Lua. It then covers how to build your own C++ RADOS class into the Ceph source tree and conduct benchmarks against performing processing on the client versus the OSD.
Chapter 16, Tiering with Ceph, explains how RADOS tiering works in Ceph, where it should be used, and its pitfalls. It takes you step-by-step through configuring tiering on a Ceph cluster and finally covers the tuning options to extract the best performance for tiering. An example using Graphite will demonstrate the value of being able to manipulate captured data to provide more meaningful output in graph form.
Chapter 17, Troubleshooting, explains how although Ceph is largely autonomous in taking care of itself and recovering from failure scenarios, in some cases, human intervention is required. We'll look at common errors and failure scenarios and how to bring Ceph back to full health by troubleshooting them.
Chapter 18, Disaster Recovery, covers situations when Ceph is in such a state that there is a complete loss of service or data loss has occurred. Less familiar recovery techniques are required to restore access to the cluster and, hopefully, recover data. This chapter arms you with the knowledge to attempt recovery in these scenarios.
Chapter 19, Operations and Maintenance, is a deep and wide inventory of day to day operations. We cover management of Ceph topologies, services, and configuration settings as well as, maintenance and debugging.
Chapter 20, Monitoring Ceph, a comprehensive collection of commands, practices, and dashboard software to help keep a close eye on the health of Ceph clusters.
Chapter 21, Performance and Stability Tuning, provides a collection of Ceph, networks, filesystems, and underlying operating system settings to optimize cluster performance and stability. Benchmarking of cluster performance is also explored.