Storage Area Networking Essentials: A Complete Guide to Understanding & Implementing SANs

Storage Area Network Essentials......Page 3
CONTENTS......Page 11
Acknowledgments......Page 21
Foreword......Page 23
Introduction......Page 25
Part One: Understanding Storage Networking......Page 31
What Is a Storage Area Network?......Page 33
What Makes a SAN Different?......Page 34
What Makes a Good SAN?......Page 36
Why Connect Storage to a Network?......Page 37
SAN Software Capability......Page 39
Summarizing SANs and Software......Page 42
Best-in-Class Computer Systems......Page 43
Heterogeneous Computer Systems......Page 44
Data Storage as a Service......Page 45
What Is This Area Thing, Anyway?......Page 46
Is NAS Just SAN Spelled Backward?......Page 47
Summary......Page 49
The SAN Paradigm Shift......Page 51
Conventional Information Processing......Page 52
The Primary SAN Paradigm Shift......Page 54
The Secondary SAN Paradigm Shift......Page 55
A Model for Enterprise Information Processing......Page 57
Change 1: More Storage for Less Money......Page 59
Change 2: More I/O for Less Money......Page 62
Change 3: Better Data Protection for Less Money......Page 65
Change 4: Global Access to Global Data......Page 66
Change 5: Less Duplication, More Consistency......Page 67
Change 6: Taking It to the Streets: Really Global Access to Really Global Data......Page 68
Change 7: Clusters Come Out of the Closet......Page 70
Change 8: Disaster Recovery—Keeping Information Processing Going and Going . . .......Page 72
Change 9: Cutting Down—More Is Not Always Better......Page 73
Change 10: Global Computing for Global Enterprises......Page 74
Summary......Page 77
A Bit of History......Page 79
Mainframe Generation I: The Rise of the Data Center......Page 80
Mainframe Generation II: Timesharing......Page 82
Online Transaction Processing: Instant Gratification for Users......Page 84
Minicomputers and Beyond: Diseconomies of Scale......Page 85
Local Area Networks......Page 87
The Standardization of Software......Page 88
The PC and Client/Server Computing......Page 89
Specialized Servers......Page 91
Limitations of Specialized Servers......Page 92
Global Enterprises and the Need for Global Data......Page 93
External Storage Subsystems......Page 95
Summary......Page 96
Killer App 1: Backup—The Application Everyone Loves to Hate......Page 97
Why a Backup Window Anyway?......Page 98
Consistent Backups......Page 99
Different Uses, Different Backups 1......Page 100
Different Uses, Different Backups 2......Page 102
Backup on a Single Computer......Page 103
A Little Relief: Multiple I/O Buses......Page 105
Backup in Client/Server Environments......Page 106
Improvement 1: LAN-free Backup......Page 108
Improvement 2: Tape Drive Sharing......Page 110
Improvement 3: The Designated Backup Server......Page 112
Improvement 4: Serverless Backup......Page 113
Improvement 5: Off-Host NAS Backup......Page 115
Killer App 2: Highly Available Data......Page 118
Mirroring 101......Page 119
Drilling Down into Mirroring: Who's Doing What to Whom......Page 120
RAID Controllers: A Lesson in Virtual Reality......Page 122
Volume Managers: The Other Disk Virtualizer......Page 123
The SAN Difference......Page 124
SANs and Available Data......Page 126
Killer App 3: Disaster Recoverability......Page 128
Split Mirrors for Backup......Page 129
Other Ways to Use Split Mirrors......Page 130
Requirements for Highly Available Computing......Page 132
Positioning Clusters: Degrees of Availability......Page 135
Tiers of Clusters......Page 136
Failover Trade-offs in Clusters......Page 139
Clusters and SANs......Page 140
Killer App 5: Data Replication......Page 143
Replication for Disaster Recoverability......Page 144
Replication for Data Publication and Consolidation......Page 145
Replication for Data Movement......Page 147
The Mechanics of Data Replication......Page 148
The Bottom Line: Continuous Global Access to Timely Information......Page 149
Summary......Page 150
Part Two: The Parts: What's in a SAN......Page 153
The Path from Data to Application......Page 157
From Bits to Records......Page 158
Data Transformation Paths......Page 160
Network Storage Systems......Page 163
Storage Network System Configurations......Page 164
NAS Appliance......Page 165
Enterprise NAS Device......Page 168
In-Band SAN Appliance......Page 169
Out-of-Band SAN Appliance......Page 171
Cluster File System with Central Metadata......Page 172
RAID Subsystem-Based Volume Replication......Page 174
Server-Based Volume Replication......Page 176
File-Based Data Replication......Page 177
Summary......Page 178
Challenges for Network Storage......Page 179
Disk Economics......Page 180
The Cost of Usable Data Center Storage......Page 181
The Bottom Line: Paying for Online Storage......Page 182
Disk Aggregation and Virtualization......Page 183
Disk Aggregation by Striping......Page 184
Keeping SAN Storage Up and Working......Page 187
RAID: Protection Against Disk Failures......Page 188
Mirroring versus RAID versus Data Striping......Page 190
Interconnect Failures......Page 191
RAID Controller Failures......Page 192
Transparent and Nontransparent Failure Tolerance......Page 193
Atomic Operations and Data Integrity......Page 194
Really Big RAID Controllers......Page 195
Volume Manager Failure Tolerance......Page 196
Choosing among Storage Options......Page 197
Summary......Page 199
Fibre Channel: The 800-Pound Gorilla of SANs......Page 201
Fibre Channel: The Chips......Page 202
Fibre Channel: The Infrastructure......Page 203
Fibre Channel Variations: Coping with Complexity......Page 204
Fibre Channel Transmission Media......Page 205
Fibre Channel Protocols: One Size Does Not Fit All......Page 207
Fibre Channel Protocol Layers......Page 208
Topology: The Shape of a Fibre Channel SAN......Page 209
Fibre Channel Fabric Topology......Page 212
Connecting Disks to a Fibre Channel Fabric......Page 215
Emerging SAN Interconnect Technologies......Page 216
New Wires for Storage Networks......Page 217
Other Storage Networking Developments......Page 219
Repartitioning Storage Functions......Page 220
Summary......Page 221
Software for SANs......Page 223
The Data Center I/O Stack......Page 224
Special Considerations for SAN Software......Page 225
Discovering Devices......Page 226
Controlling Access to Storage Devices......Page 227
Controlling Access to Data Objects......Page 228
Shared Access Data Managers......Page 229
Lock Managers......Page 230
How Lock Managers Work......Page 231
Cache and I/O Performance......Page 232
I/O Load Balancing......Page 233
Volumes: Resilience, Performance, and Flexibility......Page 234
Failure-Tolerant Volumes: What Kind of Protection?......Page 235
High-Performance Volumes: Balancing I/O Load......Page 236
System Crash Safeguards......Page 238
I/O Performance with Volumes......Page 240
Striped Volumes......Page 241
File System Space Allocation......Page 243
Extent-Based File Systems......Page 244
Preallocation and Alignment......Page 246
Back Doors for Database I/O......Page 247
Using Large Memory Effectively......Page 248
Fast Recovery from System Crashes......Page 249
File System Defragmentation......Page 251
Online File System Expansion......Page 253
Frozen Images......Page 254
Split Mirror Frozen Images......Page 255
Copy-on-Write Frozen Images......Page 256
Properties of Consistency......Page 257
Summary......Page 259
Data Replication......Page 261
Types of Data Replication......Page 262
The Nature of Data Replication......Page 263
Data Replication versus Mirroring......Page 264
Database Replication......Page 265
File System Replication......Page 266
Replication Policies......Page 267
Synchronous Replication......Page 268
Asynchronous Replication......Page 269
Using Data Replication......Page 270
Disasters and Failures......Page 271
Reciprocal Disaster Recovery......Page 272
Data Center Clusters......Page 274
Data Center Clusters in Perspective......Page 275
Why Clusters?......Page 276
Applications and Clusters......Page 277
Starting and Stopping Resources......Page 278
Failover Services......Page 279
Parallel Application Service Groups......Page 280
Managing Cluster Resources......Page 283
Cluster Interconnects......Page 284
Cluster Data Models......Page 285
Distributed Lock Management......Page 286
Volume Management in Clusters......Page 287
Cluster File Systems......Page 290
The Significance of Shared Data Clusters......Page 291
Disaster Recovery and Global Clusters......Page 292
Global Computing and Disaster Recovery......Page 295
Clusters and Storage Area Networks......Page 296
Summary......Page 297
Backup Management for SANs......Page 301
Backup......Page 302
Enterprise Backup Architecture......Page 303
Scaling Backup Operations......Page 305
Which Data Objects to Back Up......Page 307
Where to Back Up Data......Page 308
Full and Incremental Backup......Page 309
The Impact of Incremental Backup......Page 310
Combining Cumulative, Differential, and Full Backups......Page 311
Synthetic Full Backups......Page 312
Copy-on-Write Technology and Backup......Page 314
Changed Block Incremental Backup......Page 316
Factors Affecting Backup Speed and Cost......Page 318
Multiplexed Backups......Page 319
Parallelization of Large Backup Jobs......Page 320
LAN-free and Serverless Backup......Page 321
Summary......Page 323
Part Three: SAN Implementation Strategies......Page 325
Why Adopt Storage Networking?......Page 329
Technology and Business Benefits of SANs......Page 330
SAN Benefits in a Larger Information Processing Context......Page 332
How Much Downtime Is Too Much?......Page 333
Developing a SAN Deployment Strategy......Page 336
Step 1: Determining Business Information Requirements......Page 338
Step 2: Learning Technology's Capabilities......Page 339
Step 3: Matching Requirements with Technology......Page 340
Step 4: Real Planning......Page 341
Step 5: Auditing the Current Situation......Page 342
Step 6: Merging IT Plans with Enterprise Plans......Page 343
Step 7: Design and Vendor Selection......Page 344
Step 9: Iteration, Review, and Learning......Page 347
Critical Success Factors......Page 348
SAN Adoption Alternatives......Page 349
LAN-free Backup: Easing One's Way In......Page 350
Frozen Image Backup: Eliminating the Window......Page 351
Application Availability: Clustering for Failover......Page 353
Shared Data and Parallel Clustering: Application Scaling......Page 354
Data Replication I: Publication and Decision Support......Page 355
Data Replication II: Disaster Recoverability......Page 356
Going Global: Wide Area Clustering......Page 357
The Other Edge......Page 358
Summary......Page 360
SAN Management Defined......Page 361
Storage Management Tasks......Page 362
What Gets Managed in a SAN?......Page 363
Discovery: "Hello, Who's Out There?"......Page 364
But First, "Hello, I'm Here"......Page 365
What's In a Name?......Page 366
The New Meaning of Host......Page 367
Zoning: Who Gets to Do What to Whom?......Page 368
Routing: Accept What You Cannot Change......Page 370
An Ideal SAN Management Environment......Page 372
SAN Management and Online Storage Cost......Page 373
Virtualization: Allocating Capacity Rather Than Disks......Page 374
Storage Capacity......Page 376
Data Availability......Page 377
I/O Performance......Page 378
New Types of Transaction Processing......Page 382
SAN Management and Backup Cost......Page 383
SAN Management and Backup Impact......Page 385
SAN Management and Application Availability......Page 387
SAN Management and Asset Utilization......Page 388
SAN Management Tools......Page 389
Who's in Charge, Anyway? Organizing to Administer a Storage Network......Page 391
A Hidden Cost of SAN Deployment?......Page 392
The State of SAN Management......Page 393
SAN Management and Standards......Page 394
Affinity Group SAN Management Activities......Page 395
SAN Management Challenges......Page 396
SAN Management Tomorrow: The Race to the Storage Dial Tone......Page 398
Summary......Page 400
The Enterprise Data Wish List......Page 403
Low-Latency NAS......Page 404
A Single Enterprise Network Technology......Page 405
Different Models, Different Capabilities......Page 407
Availability: Abolishing Backup......Page 408
New Partitionings: Using the Intelligence in Storage Devices......Page 409
In Closing . . .......Page 410
The Storage Networking Industry Association (SNIA)......Page 411
Jiro......Page 413
The American National Standards Institute (ANSI)......Page 414
The Distributed Management Task Force (DMTF)......Page 416
Storage Systems Standards Working Group (SSSWG)......Page 417
W3C......Page 418
Dictionary of Storage Networking Terminology......Page 419
Index......Page 515