I/O Consolidation 1 Introduction 1 What Is I/O Consolidation 2 Merging the Requirements 3 Why I/O Consolidation Has Not Yet Been Successful 4 Fundamental Technologies 5 PCI-Express 5 10 Gigabit Ethernet 5 Additional Requirements 8 Buffering Requirements 8 Layer 2 Only 9 Switch Architecture 9 Low Latency 10 Native Support for Storage Traffi c 11 RDMA Support 11 Enabling Technologies 15 Introduction 15 Lossless Ethernet 15 PAUSE 15 Credits Versus PAUSE 17 PAUSE Propagation 18 Is Lossless Better? 19 Why PAUSE Is Not Widely Deployed 20 Priority-based Flow Control (PFC) 20 Additional Components 22 DCBX: Data Center Bridging eXchange 22 Bandwidth Management 23 Congestion Management 25 Delayed Drop 26 Going Beyond Spanning Tree 28 Active-Active Connectivity 32 Etherchannel 32 Virtual Switching System (VSS) 32 virtual Port Channel (vPC) 34 Ethernet Host Virtualizer 36 Layer 2 Multipath (L2MP) 38 Basic Mechanisms in L2MP 40 Cisco DBridges 47 IETF RBridges and the TRILL Project 51 VEB: Virtual Ethernet Bridging 52 Server Virtualization 53 SR-IOV 54 The IEEE Standard Effort 54 VEB in the Adapter 55 VEB in the Switch 56 VNTag 57 Fabric Extenders 59 VN-Link 60 Questions and Answers 63 Does FCoE Uses Credits? 63 High Availability of PAUSE and Credits 63 Queue Size 63 Long-Haul 63 FECN/BECN 64 Confi guration 64 Bandwidth Prioritization 64 Storage Bandwidth 64 Cisco DCB/FCoE Support 65 10GE NICs 65 IP Routing 65 Lossless Ethernet Versus Infi niband 66 Nomenclature 66 Fibre Channel over Ethernet 67 Introduction 67 Fibre Channel 69 Fibre Channel Architectural Models 71 FCoE Mapping 73 FCoE Architectural Models 74 FCoE Benefi ts 79 FCoE Data Plane 80 FCoE Topologies 82 FCoE Addressing 85 FCoE Forwarding 87 FPMAs and SPMAs 90 FIP: FCoE Initialization Protocol 92 FIP Messages 93 FIP VLAN Discovery 97 FIP Discovery 98 FIP Virtual Link Instantiation 103 FIP Virtual Link Maintenance 108 Converged Network Adapters 110 FCoE Open Software 112 Network Tools 113 FCoE and Virtualization 114 Fibre Channel Block I/O 115 iSCSI Block I/O 116 Moving a VM 117 FCoE and Block I/O 117 FCoE FAQ 118 Is FCoE Routable? 118 iSCSI Versus FCoE? 120 Does FCoE Require Gateways? 123 Case Studies 125 Introduction 125 I/O Consolidation with Discrete Servers 126 Top-of-Rack Consolidated I/O 129 Example with Blade Servers 131 Updating the Distribution Layer 133 Unifi ed Computing System 136 Bibliography 139 PCI Express 139 IEEE 802.3 139 IEEE 802.1 139 Ethernet Improvements 139 Fibre Channel 139 FCoE 140 TRILL 140 Virtualization 140 Glossary 141 Figures 145 Tables 149 Index 151
Using Fiber Channel over Ethernet (FCoE) and related technologies, data centers can consolidate data traffic onto a single network switch, simplifying their environments, promoting virtualization, and substantially reducing power and cooling costs. This emerging technology is drawing immense excitement, but few enterprise IT decision-makers and implementers truly understand it. I/O Consolidation in the Data Center is the only complete, up-to-date guide to FCoE. FCoE innovators Silvano Gai and Claudio DeSanti (chair of the T11 FCoE standards working group) systematically explain the technology: its benefits, tradeoffs, and what it will take to implement it successfully in production environments. Unlike most other discussions of FCoE, this book fully reflects the final, recently-approved industry standard. The authors also present five detailed case studies illustrating typical FCoE adoption scenarios, as well as an extensive Q and A section addressing the issues enterprise IT professionals raise most often. This is a fully updated version of Silvano Gai's privately-published book on FCoE, written for leading FCoE pioneer Nuova Systems before the company was acquired by Cisco. Nearly 12,000 copies of that book have already been distributed, demonstrating the immense interest in FCoE technology, and the scarcity of reliable information that has existed about it.