Preface前言
Data—it's a simple word that stores the past, present, and future of the entire universe, and it's the most critical element of any system that exists today. We live in an era of technology that is generating enormous amount of data each second, and with time, this data growth will be unimaginable. However, how do we store this ever-growing data such that it remains secure, reliable, and future ready? This book is about one of the storage technology game-changers that will redefine the future of storage.
数据-这是个简单的词，但它存储着整个世界的过去，现在和将来。同时，它也是现存的任何系统的最关键元素。我们生活在一个技术的时代，它每秒钟都会产生巨量的数据，并且随着时间的迁移，这些数据的量级到达了不可思议的程度。然而，我们如何才能安全，可靠并面向未来地存储这些永远都在产生的数据呢？本书就是关于一个存储技术规则的改变者，它将重新定义存储的未来。
Ceph is an open source technology that is leading the way in providing software-defined storage. Ceph is an excellent package of reliability, unified nature, and robustness. It is more complete and economic than any other storage solution present today. Ceph has developed its own entire new way of storing data; it's distributed, massively scalable, with no single point of failure, and the best part is that it runs on commodity hardware, which makes it amazingly economic. It will give you power to break the knots of expensive vendor lock-in solutions and switch to enterprise-grade open source technology for all your storage needs.
Ceph是个开源的技术，是软件定义存储的领导者。Ceph具备极好的可靠性，统一性和鲁棒性。它比现存的其它存储方案更加完整，经济。Ceph开辟了一个全新的，完整的存储数据的途径。它是分布式的，可大规模扩展，并且没有单点故障。更重要的是它运行在通用的硬件之上，这使得它具备令人惊讶的经济性。它可以让你能够打破昂贵的厂商锁定方案的枷锁，在存储上采用企业级的开源技术。
Ceph has been enriched with enterprise-class features such as high degree of reliability, robustness, scalability, erasure coding, cache tiering, and many more. The maturity that Ceph has gained over the period of a decade makes it stand out in a crowd and lead the way to storage. It is the technology of today and the future; unified Ceph storage system is the solution for whatever requirements you have for data storage. Ceph is truly unified, that is, it has files, blocks, and objects in a single storage system; this makes Ceph extremely flexible and adaptable to all your data needs. It is the answer to all the data storage problems you have.
Ceph集中了各种企业级特性，例如高度的可靠性，鲁棒性，可扩展性，纠删码，分层缓存等等。经过十年，Ceph已经足够成熟，也使得它鹤立鸡群并且引领存储的方向。它是今年以及未来的技术。统一的Ceph存储系统能够满足你在数据存储上的任何需求。Ceph是真正的统一，也就意味着在一个单一的存储系统里提供文件存储，块存储和对象存储。这使得Ceph非常灵活，并且能够适合你所有数据的需要。它就是你在数据存储上所有问题的答案。
Cloud computing is the next paradigm shift, and a storage system such as Ceph is the most essential component of the cloud infrastructure. Ceph has its big footprint in the cloud storage area. It has been a leading open source software-defined storage choice for cloud platforms such as OpenStack and CloudStack. These cloud platforms leverage the features of Ceph and deliver robust, scalable, and exabyte-level public or private cloud infrastructures. In addition to this, virtualization platforms such as KVM and libvirt support Ceph big time, and support from proprietary virtualization solutions such as VMware and HyperV is on the way.
云计算是下一个思维变革，而类似Ceph这样的存储系统是云计算设施中最关键的部件。Ceph在云存储领域有着自己巨大的足迹。它已经是OpenStack，CloudStack这样的云平台中首选的开源企业级软件定义存储。这些云平台利用Ceph的特性，提供了鲁棒的，可扩展的EB级公众或者私有云。除此之外，虚拟化平台例如KVM和libvirt非常支持Ceph，其它所有的虚拟化解决方案也支持，例如VMware，而HyperV也即将支持Ceph。
Ceph is surely the next big thing in the storage industry, which is backed by Inktank, now a part of Red Hat. Ceph has an amazing community presence and quick development cycles, making it more reliable a couple of times a year. Though Ceph is purely open source, one can enjoy enterprise-support subscriptions from Red Hat and their partner ecosystem, which is an advantage.
背靠着Inktank（现在是Red Hat的一部分），Ceph无疑是存储产业里的下一个重大突破。Ceph具有一个令人惊叹的社区，并且有快速的开发周期，使其更可靠。然而Ceph是完全开源的，用户可以享受来自Red Hat及其商业伙伴的企业级支持。这是个不错的优点。
What this book covers本书涵盖的内容
Chapter 1, Introducing Ceph Storage, covers the evolution, history, as well as the future of Ceph. This chapter explains common storage challenges and how Ceph deals with them and becomes the game-changer. It also covers a comparison of Ceph with other storage systems.
第1章，介绍Ceph存储，包括它的发展，历史，以及Ceph的特性。这章解释通用存储的挑战，以及Ceph处理这些挑战并成为规则改变者。同时也包括Ceph和其它存储系统的比较。
Chapter 2, Ceph Instant Deployment, covers instant, step-by-step practical approaches to deploy your first Ceph cluster. It includes a guided tour of creating the Ceph sandbox environment on VirtualBox as well as scaling it up.
第2章，Ceph实例部署，包含实例，搭建你的Ceph集群的实践步骤。它也包括一个用于在VirtualBox上创建Ceph沙盒环境并扩展的向导。
Chapter 3, Ceph Architecture and Components, dives deep into the Ceph internal architecture, explaining each and every component in detail. Components are explained sequentially and practically for greater learning and correlation.
第3章，Ceph架构和组件，深入Ceph内部架构，详细地解释每一个组件。通过逐个，实践式的解释组件以达到更好的学习效果，以及了解他们的相关性。
Chapter 4, Ceph Internals, covers how Ceph manages data; the practical content will help you understand every piece of it. It also covers CRUSH, placement groups, and pools in detail.
第4章，Ceph内部构件，包括Ceph怎样管理数据；实践的内容将让你了解它的每一个部分。它也包括CRUSH，placement groups，和池的细节。
Chapter 5, Deploying Ceph – the Way You Should Know, covers hardware planning required for a production-grade Ceph cluster. It also includes practical approaches of building a Ceph cluster in both the manual and automated ways using ceph-deploy.
第5章，部署Ceph-这是你应该知道的，包括企业级Ceph集群所需要的硬件计划。它也包括手动或者使用ceph-deploy自动搭建Ceph集群的实践步骤。
Chapter 6, Storage Provisioning with Ceph, includes practical hands-on approaches to explain files, blocks, and object type storage in Ceph and how to configure and provision each type. The chapter also covers snapshots, cloning, S3- and swift-compatible object storage, and much more.
第6章，Ceph的存储配置，包括用实践方式解释Ceph中的文件，块和对象三种存储类型，以及如何配置和提供每一种类型的存储。这一章也包括快照，克隆，兼容S3和swift的对象存储等等。
Chapter 7, Ceph Operations and Maintenance, covers everything to manage and operate Ceph from a system admin point of view. It includes daily operations, scaling up and down, hardware replacement, and a detailed coverage on CRUSH management and its advanced concepts.
第7章，Ceph操作和维护，涵盖从系统管理的角度管理和操作Ceph的一切事情。它包含日常操作，扩展和收缩，硬件更换，同时还包括一个详细的CRUSH管理和它的高级原理。
Chapter 8, Monitoring Your Ceph Cluster, makes you competent in monitoring your Ceph cluster and all of its components. It also covers open source Ceph monitoring dashboard projects such as Kraken and ceph-dash and their installation and configuration.
第8章，Ceph集群监控，这一章可以能让你有能力监控自己的Ceph集群和它的所有组件。本章涵盖了开源的Ceph监控台项目，例如Kraken和ceph-dash，以及它们的安装和配置。
Chapter 9, Integrating Ceph with OpenStack, covers step-by-step practical approaches to set up your own test OpenStack environment and integrating it with Ceph. It explainshow Ceph benefits OpenStack and how OpenStack components make use of Ceph.
第9章，Ceph和OpenStack集成，一步步教你搭建自己的OpenStack测试环境以及将它跟CEph集成。它解释了Ceph对OpenStack的好处，以及OpenStack组件如何使用Ceph。
Chapter 10, Ceph Performance Tuning and Benchmarking, covers advanced concepts of Ceph, such as performance tuning from both hardware and software points of view. It also includes hands-on approaches to erasure coding and cache tiering and discusses Ceph benchmarking tools.
第10章，Ceph性能调优和基准测试，涵盖了Ceph的高级原理，例如从硬件和软件角度进行性能调优。它也包含使用纠删码和分层cache的方法，以及Ceph基准测试工具的讨论。
What you need for this book阅读本书所需要的东西
The various software components required to follow the instructions in the chapters are as follows:阅读本书过程中所需要的各种软件如下：
• VirtualBox 4.0 or higher (https://www.virtualbox.org/wiki/Downloads) • CentOS operating system 6.4 (http://wiki.centos.org/Download) • Ceph software packages Version 0.78 or higher (http://ceph.com/ resources/downloads/) • S3 Client, typically S3cmd (http://s3tools.org/download) • Python-swiftclient • Kraken dashboard for monitoring (https://github.com/krakendash) • The ceph-dash dashboard for monitoring (https://github.com/Crapworks/ceph-dash) • OpenStack RDO (http://rdo.fedorapeople.org/rdo-release.rpm)
Who this book is for谁需要本书
This book targets IT and storage administrators who want to enter into the world of software-defined storage using Ceph. It also targets anyone who wishes to understand how to use Ceph and its workings to start developing and contributing to Ceph open source projects.
本书的目标读者是那些想通过Ceph进入软件定义存储领域的IT人员和存储管理员。当然它也面向希望了解如何使用Ceph，以及它如何工作，以便开始开发并为Ceph开源项目贡献的任何人。
This book also provides valuable information for IT managers and professionals trying to understand the difference between traditional and software-defined cloud storage.
本书也为想了解传统存储和软件定义存储之间差异的IT经理和专家们提供有价值信息。
Conventions
In this book, you will find a number of styles of text that distinguish between
different kinds of information. Here are some examples of these styles, and an
explanation of their meaning.
Code words in text, database table names, folder names, filenames, file extensions,
pathnames, dummy URLs, user input, and Twitter handles are shown as follows:
"The disk zap subcommand will destroy the existing partition table and content
from the disk."
A block of code is set as follows:
DEVICE=
# ceph status
New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "You can do this by selecting the ceph-node1 VM from Oracle VM VirtualBox Manager, and then clicking on the Start button."