Dell Brocade G620 Brocade 8.0.1 Fabric OS Administratiors Guide - Page 120

Lossless Dynamic Load Sharing on ports, Brocade M6505 blade server SAN I/O module

Page 120 highlights

Routing Traffic Specify -1 for fixed-port switches and -1/-1 for Brocade Backbones. These indicate "any back-end port". NOTE Frame discards can be logged as audit messages using the Fabric OS syslog facility. Lossless Dynamic Load Sharing on ports Lossless Dynamic Load Sharing (DLS) allows you to rebalance port paths without causing input/output (I/O) failures. For devices where in-order delivery (IOD) of frames is required, you can set IOD separately. You can use this feature with the following hardware: ∙ Brocade 6505 ∙ Brocade 6510 ∙ Brocade 6520 ∙ Brocade G620 ∙ Brocade M6505 blade server SAN I/O module ∙ Brocade 6543 blade server SAN I/O module ∙ Brocade 6545 blade server SAN I/O module ∙ Brocade 6546 blade server SAN I/O module ∙ Brocade 6547 blade server SAN I/O module ∙ Brocade 6548 blade server SAN I/O module ∙ Brocade 6558 blade server SAN I/O module ∙ Brocade DCX 8510 Directors with the following blades: - Brocade FC16-32, FC16-48, FC16-64 port blades ∙ Brocade X6 Directors with the following blades: - Brocade FC32-48 port blades Lossless DLS must be implemented along the path between the target and the initiator. You can use Lossless DLS on ports connecting switches to perform the following functions: ∙ Eliminate dropped frames and I/O failures by rebalancing the paths going over the ISLs whenever there is a fabric event that might result in suboptimal utilization of the ISLs. ∙ Eliminate the frame delay caused by establishing a new path when a topology change occurs. Lossless mode means no frame loss during a rebalance and only takes effect if DLS is enabled. Lossless DLS can be enabled on a fabric topology to have zero frame drops during rebalance operations. If the end device also requires the order of frames to be maintained during the rebalance operation, then IOD must be enabled. However, this combination of Lossless DLS and IOD is supported only in specific topologies, such as in a FICON environment. You can disable or enable IOD when Lossless DLS is enabled. You can also choose between exchange- or port-based policies with Lossless DLS. The following events cause a rebalance: ∙ Adding a redundant E_Port ∙ Adding a slave E_Port ∙ Removing the last E_Port from a neighbor domain (However, frame loss occurs on traffic flows to this port.) ∙ Removing an F_Port (However, frame loss occurs on traffic flows to this port.) Lossless DLS does the following whenever paths need to be rebalanced: 1. Pauses ingress traffic by not returning credits. Frames that are already in transit are not dropped. Brocade Fabric OS Administration Guide, 8.0.1 120 53-1004111-02

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
  • 201
  • 202
  • 203
  • 204
  • 205
  • 206
  • 207
  • 208
  • 209
  • 210
  • 211
  • 212
  • 213
  • 214
  • 215
  • 216
  • 217
  • 218
  • 219
  • 220
  • 221
  • 222
  • 223
  • 224
  • 225
  • 226
  • 227
  • 228
  • 229
  • 230
  • 231
  • 232
  • 233
  • 234
  • 235
  • 236
  • 237
  • 238
  • 239
  • 240
  • 241
  • 242
  • 243
  • 244
  • 245
  • 246
  • 247
  • 248
  • 249
  • 250
  • 251
  • 252
  • 253
  • 254
  • 255
  • 256
  • 257
  • 258
  • 259
  • 260
  • 261
  • 262
  • 263
  • 264
  • 265
  • 266
  • 267
  • 268
  • 269
  • 270
  • 271
  • 272
  • 273
  • 274
  • 275
  • 276
  • 277
  • 278
  • 279
  • 280
  • 281
  • 282
  • 283
  • 284
  • 285
  • 286
  • 287
  • 288
  • 289
  • 290
  • 291
  • 292
  • 293
  • 294
  • 295
  • 296
  • 297
  • 298
  • 299
  • 300
  • 301
  • 302
  • 303
  • 304
  • 305
  • 306
  • 307
  • 308
  • 309
  • 310
  • 311
  • 312
  • 313
  • 314
  • 315
  • 316
  • 317
  • 318
  • 319
  • 320
  • 321
  • 322
  • 323
  • 324
  • 325
  • 326
  • 327
  • 328
  • 329
  • 330
  • 331
  • 332
  • 333
  • 334
  • 335
  • 336
  • 337
  • 338
  • 339
  • 340
  • 341
  • 342
  • 343
  • 344
  • 345
  • 346
  • 347
  • 348
  • 349
  • 350
  • 351
  • 352
  • 353
  • 354
  • 355
  • 356
  • 357
  • 358
  • 359
  • 360
  • 361
  • 362
  • 363
  • 364
  • 365
  • 366
  • 367
  • 368
  • 369
  • 370
  • 371
  • 372
  • 373
  • 374
  • 375
  • 376
  • 377
  • 378
  • 379
  • 380
  • 381
  • 382
  • 383
  • 384
  • 385
  • 386
  • 387
  • 388
  • 389
  • 390
  • 391
  • 392
  • 393
  • 394
  • 395
  • 396
  • 397
  • 398
  • 399
  • 400
  • 401
  • 402
  • 403
  • 404
  • 405
  • 406
  • 407
  • 408
  • 409
  • 410
  • 411
  • 412
  • 413
  • 414
  • 415
  • 416
  • 417
  • 418
  • 419
  • 420
  • 421
  • 422
  • 423
  • 424
  • 425
  • 426
  • 427
  • 428
  • 429
  • 430
  • 431
  • 432
  • 433
  • 434
  • 435
  • 436
  • 437
  • 438
  • 439
  • 440
  • 441
  • 442
  • 443
  • 444
  • 445
  • 446
  • 447
  • 448
  • 449
  • 450
  • 451
  • 452
  • 453
  • 454
  • 455
  • 456
  • 457
  • 458
  • 459
  • 460
  • 461
  • 462
  • 463
  • 464
  • 465
  • 466
  • 467
  • 468
  • 469
  • 470
  • 471
  • 472
  • 473
  • 474
  • 475
  • 476
  • 477
  • 478
  • 479
  • 480
  • 481
  • 482
  • 483
  • 484
  • 485
  • 486
  • 487
  • 488
  • 489
  • 490
  • 491
  • 492
  • 493
  • 494
  • 495
  • 496
  • 497
  • 498
  • 499
  • 500
  • 501
  • 502
  • 503
  • 504
  • 505
  • 506
  • 507
  • 508
  • 509
  • 510
  • 511
  • 512
  • 513
  • 514
  • 515
  • 516
  • 517
  • 518
  • 519
  • 520
  • 521
  • 522
  • 523
  • 524
  • 525
  • 526
  • 527
  • 528
  • 529
  • 530
  • 531
  • 532
  • 533
  • 534
  • 535
  • 536
  • 537
  • 538
  • 539
  • 540
  • 541
  • 542
  • 543
  • 544
  • 545
  • 546
  • 547
  • 548
  • 549
  • 550
  • 551

Specify
-1
for fixed-port switches and
-1/-1
for Brocade Backbones. These indicate “any back-end port”.
NOTE
Frame discards can be logged as audit messages using the Fabric OS syslog facility.
Lossless Dynamic Load Sharing on ports
Lossless Dynamic Load Sharing (DLS) allows you to rebalance port paths without causing input/output (I/O) failures. For devices where
in-order delivery (IOD) of frames is required, you can set IOD separately. You can use this feature with the following hardware:
Brocade 6505
Brocade 6510
Brocade 6520
Brocade G620
Brocade M6505 blade server SAN I/O module
Brocade 6543 blade server SAN I/O module
Brocade 6545 blade server SAN I/O module
Brocade 6546 blade server SAN I/O module
Brocade 6547 blade server SAN I/O module
Brocade 6548 blade server SAN I/O module
Brocade 6558 blade server SAN I/O module
Brocade DCX 8510 Directors with the following blades:
Brocade FC16-32, FC16-48, FC16-64 port blades
Brocade X6 Directors with the following blades:
Brocade FC32-48 port blades
Lossless DLS must be implemented along the path between the target and the initiator. You can use Lossless DLS on ports connecting
switches to perform the following functions:
Eliminate dropped frames and I/O failures by rebalancing the paths going over the ISLs whenever there is a fabric event that
might result in suboptimal utilization of the ISLs.
Eliminate the frame delay caused by establishing a new path when a topology change occurs.
Lossless mode means no frame loss during a rebalance and only takes effect if DLS is enabled. Lossless DLS can be enabled on a
fabric topology to have zero frame drops during rebalance operations. If the end device also requires the order of frames to be
maintained during the rebalance operation, then IOD must be enabled. However, this combination of Lossless DLS and IOD is
supported only in specific topologies, such as in a FICON environment.
You can disable or enable IOD when Lossless DLS is enabled. You can also choose between exchange- or port-based policies with
Lossless DLS. The following events cause a rebalance:
Adding a redundant E_Port
Adding a slave E_Port
Removing the last E_Port from a neighbor domain (However, frame loss occurs on traffic flows to this port.)
Removing an F_Port (However, frame loss occurs on traffic flows to this port.)
Lossless DLS does the following whenever paths need to be rebalanced:
1.
Pauses ingress traffic by not returning credits. Frames that are already in transit are not dropped.
Routing Traffic
Brocade Fabric OS Administration Guide, 8.0.1
120
53-1004111-02