ceph/doc/cephfs/mds-config-ref.rst

   1 ======================
   2  MDS Config Reference
   3 ======================
   4
   5 ``mds cache memory limit``
   6
   7 :Description: The memory limit the MDS should enforce for its cache.
   8 :Type:  64-bit Integer Unsigned
   9 :Default: ``4G``
  10
  11 ``mds cache reservation``
  12
  13 :Description: The cache reservation (memory or inodes) for the MDS cache to maintain.
  14               Once the MDS begins dipping into its reservation, it will recall
  15               client state until its cache size shrinks to restore the
  16               reservation.
  17 :Type:  Float
  18 :Default: ``0.05``
  19
  20
  21 ``mds cache mid``
  22
  23 :Description: The insertion point for new items in the cache LRU
  24               (from the top).
  25
  26 :Type:  Float
  27 :Default: ``0.7``
  28
  29
  30 ``mds dir commit ratio``
  31
  32 :Description: The fraction of directory that is dirty before Ceph commits using
  33               a full update (instead of partial update).
  34
  35 :Type:  Float
  36 :Default: ``0.5``
  37
  38
  39 ``mds dir max commit size``
  40
  41 :Description: The maximum size of a directory update before Ceph breaks it into
  42               smaller transactions) (MB).
  43
  44 :Type:  32-bit Integer
  45 :Default: ``90``
  46
  47
  48 ``mds decay halflife``
  49
  50 :Description: The half-life of MDS cache temperature.
  51 :Type:  Float
  52 :Default: ``5``
  53
  54 ``mds beacon interval``
  55
  56 :Description: The frequency (in seconds) of beacon messages sent
  57               to the monitor.
  58
  59 :Type:  Float
  60 :Default: ``4``
  61
  62
  63 ``mds beacon grace``
  64
  65 :Description: The interval without beacons before Ceph declares an MDS laggy
  66               (and possibly replace it).
  67
  68 :Type:  Float
  69 :Default: ``15``
  70
  71
  72 ``mds blacklist interval``
  73
  74 :Description: The blacklist duration for failed MDSs in the OSD map. Note,
  75               this controls how long failed MDS daemons will stay in the
  76               OSDMap blacklist. It has no effect on how long something is
  77               blacklisted when the administrator blacklists it manually. For
  78               example, ``ceph osd blacklist add`` will still use the default
  79               blacklist time.
  80 :Type:  Float
  81 :Default: ``24.0*60.0``
  82
  83
  84 ``mds reconnect timeout``
  85
  86 :Description: The interval (in seconds) to wait for clients to reconnect
  87               during MDS restart.
  88
  89 :Type:  Float
  90 :Default: ``45``
  91
  92
  93 ``mds tick interval``
  94
  95 :Description: How frequently the MDS performs internal periodic tasks.
  96 :Type:  Float
  97 :Default: ``5``
  98
  99
 100 ``mds dirstat min interval``
 101
 102 :Description: The minimum interval (in seconds) to try to avoid propagating
 103               recursive stats up the tree.
 104
 105 :Type:  Float
 106 :Default: ``1``
 107
 108 ``mds scatter nudge interval``
 109
 110 :Description: How quickly dirstat changes propagate up.
 111 :Type:  Float
 112 :Default: ``5``
 113
 114
 115 ``mds client prealloc inos``
 116
 117 :Description: The number of inode numbers to preallocate per client session.
 118 :Type:  32-bit Integer
 119 :Default: ``1000``
 120
 121
 122 ``mds early reply``
 123
 124 :Description: Determines whether the MDS should allow clients to see request
 125               results before they commit to the journal.
 126
 127 :Type:  Boolean
 128 :Default: ``true``
 129
 130
 131 ``mds default dir hash``
 132
 133 :Description: The function to use for hashing files across directory fragments.
 134 :Type:  32-bit Integer
 135 :Default: ``2`` (i.e., rjenkins)
 136
 137
 138 ``mds log skip corrupt events``
 139
 140 :Description: Determines whether the MDS should try to skip corrupt journal
 141               events during journal replay.
 142
 143 :Type:  Boolean
 144 :Default:  ``false``
 145
 146
 147 ``mds log max events``
 148
 149 :Description: The maximum events in the journal before we initiate trimming.
 150               Set to ``-1`` to disable limits.
 151
 152 :Type:  32-bit Integer
 153 :Default: ``-1``
 154
 155
 156 ``mds log max segments``
 157
 158 :Description: The maximum number of segments (objects) in the journal before
 159               we initiate trimming. Set to ``-1`` to disable limits.
 160
 161 :Type:  32-bit Integer
 162 :Default: ``128``
 163
 164
 165 ``mds bal sample interval``
 166
 167 :Description: Determines how frequently to sample directory temperature
 168               (for fragmentation decisions).
 169
 170 :Type:  Float
 171 :Default: ``3``
 172
 173
 174 ``mds bal replicate threshold``
 175
 176 :Description: The maximum temperature before Ceph attempts to replicate
 177               metadata to other nodes.
 178
 179 :Type:  Float
 180 :Default: ``8000``
 181
 182
 183 ``mds bal unreplicate threshold``
 184
 185 :Description: The minimum temperature before Ceph stops replicating
 186               metadata to other nodes.
 187
 188 :Type:  Float
 189 :Default: ``0``
 190
 191
 192 ``mds bal split size``
 193
 194 :Description: The maximum directory size before the MDS will split a directory
 195               fragment into smaller bits.
 196
 197 :Type:  32-bit Integer
 198 :Default: ``10000``
 199
 200
 201 ``mds bal split rd``
 202
 203 :Description: The maximum directory read temperature before Ceph splits
 204               a directory fragment.
 205
 206 :Type:  Float
 207 :Default: ``25000``
 208
 209
 210 ``mds bal split wr``
 211
 212 :Description: The maximum directory write temperature before Ceph splits
 213               a directory fragment.
 214
 215 :Type:  Float
 216 :Default: ``10000``
 217
 218
 219 ``mds bal split bits``
 220
 221 :Description: The number of bits by which to split a directory fragment.
 222 :Type:  32-bit Integer
 223 :Default: ``3``
 224
 225
 226 ``mds bal merge size``
 227
 228 :Description: The minimum directory size before Ceph tries to merge
 229               adjacent directory fragments.
 230
 231 :Type:  32-bit Integer
 232 :Default: ``50``
 233
 234
 235 ``mds bal interval``
 236
 237 :Description: The frequency (in seconds) of workload exchanges between MDSs.
 238 :Type:  32-bit Integer
 239 :Default: ``10``
 240
 241
 242 ``mds bal fragment interval``
 243
 244 :Description: The delay (in seconds) between a fragment being eligible for split
 245               or merge and executing the fragmentation change.
 246 :Type:  32-bit Integer
 247 :Default: ``5``
 248
 249
 250 ``mds bal fragment fast factor``
 251
 252 :Description: The ratio by which frags may exceed the split size before
 253               a split is executed immediately (skipping the fragment interval)
 254 :Type:  Float
 255 :Default: ``1.5``
 256
 257 ``mds bal fragment size max``
 258
 259 :Description: The maximum size of a fragment before any new entries
 260               are rejected with ENOSPC.
 261 :Type:  32-bit Integer
 262 :Default: ``100000``
 263
 264 ``mds bal idle threshold``
 265
 266 :Description: The minimum temperature before Ceph migrates a subtree
 267               back to its parent.
 268
 269 :Type:  Float
 270 :Default: ``0``
 271
 272
 273 ``mds bal max``
 274
 275 :Description: The number of iterations to run balancer before Ceph stops.
 276               (used for testing purposes only)
 277
 278 :Type:  32-bit Integer
 279 :Default: ``-1``
 280
 281
 282 ``mds bal max until``
 283
 284 :Description: The number of seconds to run balancer before Ceph stops.
 285               (used for testing purposes only)
 286
 287 :Type:  32-bit Integer
 288 :Default: ``-1``
 289
 290
 291 ``mds bal mode``
 292
 293 :Description: The method for calculating MDS load.
 294
 295               - ``0`` = Hybrid.
 296               - ``1`` = Request rate and latency.
 297               - ``2`` = CPU load.
 298
 299 :Type:  32-bit Integer
 300 :Default: ``0``
 301
 302
 303 ``mds bal min rebalance``
 304
 305 :Description: The minimum subtree temperature before Ceph migrates.
 306 :Type:  Float
 307 :Default: ``0.1``
 308
 309
 310 ``mds bal min start``
 311
 312 :Description: The minimum subtree temperature before Ceph searches a subtree.
 313 :Type:  Float
 314 :Default: ``0.2``
 315
 316
 317 ``mds bal need min``
 318
 319 :Description: The minimum fraction of target subtree size to accept.
 320 :Type:  Float
 321 :Default: ``0.8``
 322
 323
 324 ``mds bal need max``
 325
 326 :Description: The maximum fraction of target subtree size to accept.
 327 :Type:  Float
 328 :Default: ``1.2``
 329
 330
 331 ``mds bal midchunk``
 332
 333 :Description: Ceph will migrate any subtree that is larger than this fraction
 334               of the target subtree size.
 335
 336 :Type:  Float
 337 :Default: ``0.3``
 338
 339
 340 ``mds bal minchunk``
 341
 342 :Description: Ceph will ignore any subtree that is smaller than this fraction
 343               of the target subtree size.
 344
 345 :Type:  Float
 346 :Default: ``0.001``
 347
 348
 349 ``mds bal target removal min``
 350
 351 :Description: The minimum number of balancer iterations before Ceph removes
 352               an old MDS target from the MDS map.
 353
 354 :Type:  32-bit Integer
 355 :Default: ``5``
 356
 357
 358 ``mds bal target removal max``
 359
 360 :Description: The maximum number of balancer iteration before Ceph removes
 361               an old MDS target from the MDS map.
 362
 363 :Type:  32-bit Integer
 364 :Default: ``10``
 365
 366
 367 ``mds replay interval``
 368
 369 :Description: The journal poll interval when in standby-replay mode.
 370               ("hot standby")
 371
 372 :Type:  Float
 373 :Default: ``1``
 374
 375
 376 ``mds shutdown check``
 377
 378 :Description: The interval for polling the cache during MDS shutdown.
 379 :Type:  32-bit Integer
 380 :Default: ``0``
 381
 382
 383 ``mds thrash exports``
 384
 385 :Description: Ceph will randomly export subtrees between nodes (testing only).
 386 :Type:  32-bit Integer
 387 :Default: ``0``
 388
 389
 390 ``mds thrash fragments``
 391
 392 :Description: Ceph will randomly fragment or merge directories.
 393 :Type:  32-bit Integer
 394 :Default: ``0``
 395
 396
 397 ``mds dump cache on map``
 398
 399 :Description: Ceph will dump the MDS cache contents to a file on each MDSMap.
 400 :Type:  Boolean
 401 :Default:  ``false``
 402
 403
 404 ``mds dump cache after rejoin``
 405
 406 :Description: Ceph will dump MDS cache contents to a file after
 407               rejoining the cache (during recovery).
 408
 409 :Type:  Boolean
 410 :Default:  ``false``
 411
 412
 413 ``mds verify scatter``
 414
 415 :Description: Ceph will assert that various scatter/gather invariants
 416               are ``true`` (developers only).
 417
 418 :Type:  Boolean
 419 :Default:  ``false``
 420
 421
 422 ``mds debug scatterstat``
 423
 424 :Description: Ceph will assert that various recursive stat invariants
 425               are ``true`` (for developers only).
 426
 427 :Type:  Boolean
 428 :Default:  ``false``
 429
 430
 431 ``mds debug frag``
 432
 433 :Description: Ceph will verify directory fragmentation invariants
 434               when convenient (developers only).
 435
 436 :Type:  Boolean
 437 :Default:  ``false``
 438
 439
 440 ``mds debug auth pins``
 441
 442 :Description: The debug auth pin invariants (for developers only).
 443 :Type:  Boolean
 444 :Default:  ``false``
 445
 446
 447 ``mds debug subtrees``
 448
 449 :Description: The debug subtree invariants (for developers only).
 450 :Type:  Boolean
 451 :Default:  ``false``
 452
 453
 454 ``mds kill mdstable at``
 455
 456 :Description: Ceph will inject MDS failure in MDSTable code
 457               (for developers only).
 458
 459 :Type:  32-bit Integer
 460 :Default: ``0``
 461
 462
 463 ``mds kill export at``
 464
 465 :Description: Ceph will inject MDS failure in the subtree export code
 466               (for developers only).
 467
 468 :Type:  32-bit Integer
 469 :Default: ``0``
 470
 471
 472 ``mds kill import at``
 473
 474 :Description: Ceph will inject MDS failure in the subtree import code
 475               (for developers only).
 476
 477 :Type:  32-bit Integer
 478 :Default: ``0``
 479
 480
 481 ``mds kill link at``
 482
 483 :Description: Ceph will inject MDS failure in hard link code
 484               (for developers only).
 485
 486 :Type:  32-bit Integer
 487 :Default: ``0``
 488
 489
 490 ``mds kill rename at``
 491
 492 :Description: Ceph will inject MDS failure in the rename code
 493               (for developers only).
 494
 495 :Type:  32-bit Integer
 496 :Default: ``0``
 497
 498
 499 ``mds wipe sessions``
 500
 501 :Description: Ceph will delete all client sessions on startup
 502               (for testing only).
 503
 504 :Type:  Boolean
 505 :Default: ``false``
 506
 507
 508 ``mds wipe ino prealloc``
 509
 510 :Description: Ceph will delete ino preallocation metadata on startup
 511               (for testing only).
 512
 513 :Type:  Boolean
 514 :Default: ``false``
 515
 516
 517 ``mds skip ino``
 518
 519 :Description: The number of inode numbers to skip on startup
 520               (for testing only).
 521
 522 :Type:  32-bit Integer
 523 :Default: ``0``
 524
 525
 526 ``mds min caps per client``
 527
 528 :Description: Set the minimum number of capabilities a client may hold.
 529 :Type: Integer
 530 :Default: ``100``
 531
 532
 533 ``mds max ratio caps per client``
 534
 535 :Description: Set the maximum ratio of current caps that may be recalled during MDS cache pressure.
 536 :Type: Float
 537 :Default: ``0.8``