大话存储后传：次世代数据存储思维与技术

　　冬瓜哥（张冬），现任某半导体公司系统架构师，著有《大话存储》系列图书。存储领域技术专家和布道者。

冬瓜哥对技术的追求已经到了“痴迷”的境界，与10年前相比，文笔解析更为到位，技术理解更为精准。其公众号的每篇文章，都是存储业界风向标。

　　前言
　　眨眼间，距离《大话存储》一书出版已经8年了。在这8年间，冬瓜哥也一直在不断地学习积累并输出，并在2015年5月份创立了微信公众号“大话存储”，继续总结和输出各类存储系统知识，皆为原创。本书即对这一年多来冬瓜哥的输出文章进行了整理再加工，并特意增加了30%的从未发布的额外内容。
　　如果说《大话存储》系列图书是一部系统性讲述存储系统底层的小说的话，那么本书相当于一部散文集，全篇形散神聚，自由穿梭于存储和计算机系统的底层和顶层世界中。其中的每一篇都表述了某个领域、课题或者技术，并围绕该技术展开叙述。冬瓜哥把全书划分为12个技术领域部分，每一个部分又包含多篇相关的文章。
　　其中有些文章中带有鄙人手绘的图片，为了保持原汁原味，决定保留原样，如果侮辱了你的审美观，请见谅。
　　阅读本书要求对存储系统有一定了解，最好是相当了解，否则会感到比较吃力。不过，吃力是好事，证明有提升空间，那就赶紧去买本《大话存储终极版》看看正传吧，然后再来看后传。当年冬瓜哥看一些文档的时候，也是很吃力，但是总感觉很有意思，也就坚持了下来。
　　可能有人会想，后续会不会有《大话存储外传》呢？嗯，或许吧，顺其自然！
　　冬瓜哥

第一章 灵活的数据布局 ·········································································1
1.1 Raid1.0和Raid1.5 ······························································································2
1.2 Raid5EE和Raid2.0 ·····························································································4
1.3 Lun2.0/SmartMotion ························································································13
第二章 应用感知及可视化存储智能 ·····················································23
2.1 应用感知精细化自动存储分层······································································25
2.2 应用感知精细化SmartMotion ········································································27
2.3 应用感知精细化QoS ······················································································28
2.4 产品化及可视化展现······················································································31
2.5 包装概念制作PPT ···························································································43
2.6 评浪潮“活性”存储概念··············································································49
第三章 存储类芯片 ··············································································53
3.1 通道及Raid控制器架构 ··················································································54
3.2 SAS Expander架构 ··························································································60
第四章 储海钩沉 ··················································································65
4.1 你绝对想不到的两种高格调存储器······························································66
4.2 JBOD里都有什么····························································································70

4.3 Raid4校验盘之殇 ····························································································72
4.4 为什么说Raid卡是台小电脑 ··········································································73
4.5 为什么Raid卡电池被换为超级电容 ······························································74
4.6 固件和微码到底什么区别··············································································75
4.7 FC成环器内部真的是个环吗 ·········································································76
4.8 为什么说SAS、FC对CPU耗费比TCPIP+以太网低 ····································77
4.9 双控存储之间的心跳线都跑了哪些流量······················································78
第五章集群和多控制器 ······································································· 79
5.1 浅谈双活和多路径··························································································80
5.2 “浅”谈容灾和双活数据中心（上）··························································82
5.3 “浅”谈容灾和双活数据中心（下）··························································87
5.4 集群文件系统架构演变深度梳理图解··························································96
5.5 从多控缓存管理到集群锁············································································107
5.6 共享式与分布式各论····················································································115
5.7 “冬瓜哥画PPT”双活是个坑 ·····································································118
第六章传统存储系统 ········································································· 121
6.1 与存储系统相关的一些基本话题分享························································122
6.2 高端存储系统江湖风云录！········································································133
6.3 惊了！原来高端存储架构是这样演进的！················································145
6.4 传统高端存储系统把数据缓存集中外置一石三鸟····································155
6.5 传统外置存储已近黄昏················································································156
6.6 存储圈老炮大战小鲜肉················································································166
6.7 传统存储老矣，新兴存储能当大任否？····················································167
第七章次世代存储系统 ····································································· 185
7.1 一杆老枪照玩次世代存储系统····································································187
7.2 最有传统存储格调的次世代存储系统························································192
7.3 最适合大规模数据中心的次世代存储系统················································203
7.4 最高性能的次世代存储系统········································································206
7.5 最具备感知应用能力的次世代存储系统····················································214
7.6 最具有数据管理灵活性的次时代存储系统················································225

第八章光存储系统············································································ 237
8.1 光存储基本原理····························································································238
8.2 神秘的激光头及蓝光技术············································································244
8.3 剖析蓝光存储系统························································································249
8.4 光存储系统生态····························································································253
8.5 站在未来看现在····························································································259
第九章体系结构 ················································································ 263
9.1 大话众核心处理器体系结构········································································264
9.2 致敬龙芯！冬瓜哥手工设计了一个CPU译码器！ ····································271
9.3 NUNA体系结构首次落地InCloudRack机柜 ···············································274
9.4 评宏杉科技的CloudSAN架构 ······································································278
9.5 内存竟然还能这么玩？！············································································283
9.6 PCIe交换，什么鬼？····················································································293
9.7 聊聊FPGA/GPCPU/PCIe/Cache-Coherency ················································300
9.8 【科普】超算到底是怎样算的？································································305
第十章 I/O 协议栈及性能分析 ···························································· 317
10.1 最完整的存储系统接口/协议/连接方式总结 ···········································318
10.2 I/O协议栈前沿技术研究动态 ····································································332
10.3 Raid组的Stripe Size到底设置为多少合适？ ·············································344
10.4 并发I/O——系统性能的根本！ ································································347
10.5 关于I/O时延你被骗了多久？ ····································································349
10.6 如何测得整条I/O路径上的并发度？ ························································351
10.7 队列深度、时延、并发度、吞吐量的关系到底是什么··························351
10.8 为什么Raid对于某些场景没有任何提速作用？ ······································365
10.9 为什么测试时性能出色，上线时却惨不忍睹？······································366
10.10 队列深度过浅有什么影响？····································································368
10.11 队列深度调节为多大最理想？ ································································369
10.12 机械盘的随机I/O平均时延为什么有一过性降低？ ······························370
10.13 数据布局到底是怎么影响性能的？························································371
10.14 关于同步I/O与阻塞I/O的误解 ·································································374
10.15 原子写，什么鬼？！················································································375

10.16 何不做个USB Target？ ·············································································385
10.17 冬瓜哥的一项新存储技术专利已正式通过············································385
10.18 小梳理一下iSCSI底层 ··············································································394
10.19 FC的4次Login过程简析 ···········································································396
第十一章存储软件············································································ 397
11.1 Thin就是个坑谁用谁找抽！······································································398
11.2 存储系统OS变迁 ·························································································400
第十二章固态存储············································································ 409
12.1 浅析固态介质在存储系统中的应用方式··················································410
12.2 关于SSD元数据及掉电保护的误解··························································420
12.3 关于闪存FTL的Host Base和Device Based的误解 ····································421
12.4 关于SSD HMB与CMB ···············································································423
12.5 同有科技展翅归来······················································································424
12.6 和老唐说相声之SSD性能测试之“玉”··················································435
12.7 固态盘到底该怎么做Raid？ ······································································441
12.8 当Raid2.0遇上全固态存储 ·········································································448
12.9 上/下页、快/慢页、MSB/LSB都些什么鬼？ ··········································451
12.10 关于对MSB/LSB写0时的步骤 ·································································457