IBM TS2340 User Guide - Page 128

alternate_pathing=1, file: options lin_tape

Page 128 highlights

Linux Device Driver (lin_tape) Data Path Failover and Load Balancing Support for Tape Drives Data path failover support is not enabled automatically when the device driver is installed. The Linux lin_tape device driver provides a driver parameter alternate_pathing for you to enable the data path failover. To enable the failover support in the lin_tape device driver software, you need to perform the following steps after installing the lin_tape rpm package. >lin_taped stop (stop the lin_taped daemon) >rmmod lin_tape (unload the lin_tape driver from the memory If you have IBM 3592 tape drives, add the following line in your /etc/modules.conf file for 2.4 kernels or /etc/modprobe.conf.local file for 2.6 kernels: options lin_tape alternate_pathing=1 If you have IBM LTO tape drives, the library needs to have path failover feature code. The data path failover license keys are needed to enable the failover if you are running LTO2 drives or if you are running LTO3 drives with old levels of drive code. DPF keys do not need to be added if you are running the latest drive code on LTO3 or LTO4 drives. Add the following line in your /etc/modules.conf file for 2.4 kernels or /etc/modprobe.conf.local file for 2.6 kernels: options lin_tape alternate_pathing=1 dpf_keys="abcdefghijklmnop" ″abckdefghijklmnop″ is an example of a data path failover feature key. If you have multiple libraries and multiple data path failover feature keys, input your keys as follows: dpf_keys="key1;key2;..." Save the file, then run the following commands: >depmod >modprobe lin_tape (re-load the lin_tape driver into memory) >lin_taped (re-start lin_taped daemon) You may ignore the ″Unresolved symbols in /lib/modules//drivers/scsi/lin_tape.ko″ message after the depmod command. You can check if the lin_tape driver has recognized multiple paths for your tape drive by reading the /proc/scsi/IBMtape file: >cat /proc/scsi/IBMtape If your tape drive lists ″Primary″ or ″Alternate″ under ″FO Path″, you have successfully enabled data path failover feature for your tape drive. If it is ″NA″ listed under ″FO Path″, then the data path failover is not enabled. After the path failover support is enabled, it remains set until the lin_tape driver is reloaded with the alternate_pathing driver parameter set to OFF . The path failover setting is retained even if the system is rebooted. If you want to turn off the data path failover feature in the lin_tape device driver, you may do the following steps: >lin_taped stop >rmmod lin_tape Delete the following line in your /etc/modules.conf file: options lin_tape alternate_pathing=1 110 IBM Tape Device Drivers Installation and User's Guide

  • 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

Data Path Failover and Load Balancing Support for Tape Drives
Data path failover support is not enabled automatically when the device driver is
installed. The Linux lin_tape device driver provides a driver parameter
alternate_pathing
for you to enable the data path failover.
To enable the failover support in the lin_tape device driver software, you need to
perform the following steps after installing the lin_tape
rpm
package.
>lin_taped stop (stop the lin_taped daemon)
>rmmod lin_tape (unload the lin_tape driver from the memory
If you have IBM 3592 tape drives, add the following line in your
/etc/modules.conf file for 2.4 kernels or /etc/modprobe.conf.local file for 2.6
kernels:
options lin_tape alternate_pathing=1
If you have IBM LTO tape drives, the library needs to have path failover feature
code. The data path failover license keys are needed to enable the failover if you
are running LTO2 drives or if you are running LTO3 drives with old levels of drive
code. DPF keys do not need to be added if you are running the latest drive code
on LTO3 or LTO4 drives.
Add the following line in your /etc/modules.conf file for 2.4 kernels or
/etc/modprobe.conf.local file for 2.6 kernels:
options lin_tape alternate_pathing=1 dpf_keys="abcdefghijklmnop"
abckdefghijklmnop
is an example of a data path failover feature key. If you have
multiple libraries and multiple data path failover feature keys, input your keys as
follows:
dpf_keys="key1;key2;..."
Save the file, then run the following commands:
>depmod
>modprobe lin_tape (re-load the lin_tape driver into memory)
>lin_taped (re-start lin_taped daemon)
You may ignore the
Unresolved symbols in /lib/modules/<your kernel
name>/drivers/scsi/lin_tape.ko
message after the
depmod
command. You can check if
the lin_tape driver has recognized multiple paths for your tape drive by reading
the
/proc/scsi/IBMtape
file:
>cat /proc/scsi/IBMtape
If your tape drive lists
Primary
or
Alternate
under
FO Path
, you have
successfully enabled data path failover feature for your tape drive. If it is
NA
listed under
FO Path
, then the data path failover is not enabled. After the path
failover support is enabled, it remains set until the lin_tape driver is reloaded with
the
alternate_pathing
driver parameter set to OFF . The path failover setting is
retained even if the system is rebooted. If you want to turn off the data path
failover feature in the lin_tape device driver, you may do the following steps:
>lin_taped stop
>rmmod lin_tape
Delete the following line in your
/etc/modules.conf
file: options lin_tape
alternate_pathing=1
Linux Device Driver (lin_tape)
110
IBM Tape Device Drivers Installation and User’s Guide