drivers/staging/lustre/sysfs-fs-lustre

   1 What:           /sys/fs/lustre/version
   2 Date:           May 2015
   3 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
   4 Description:
   5                 Shows current running lustre version.
   6
   7 What:           /sys/fs/lustre/pinger
   8 Date:           May 2015
   9 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  10 Description:
  11                 Shows if the lustre module has pinger support.
  12                 "on" means yes and "off" means no.
  13
  14 What:           /sys/fs/lustre/health_check
  15 Date:           May 2015
  16 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  17 Description:
  18                 Shows whenever current system state believed to be "healthy",
  19                 "NOT HEALTHY", or "LBUG" whenever lustre has experienced
  20                 an internal assertion failure
  21
  22 What:           /sys/fs/lustre/jobid_name
  23 Date:           May 2015
  24 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  25 Description:
  26                 Currently running job "name" for this node to be transferred
  27                 to Lustre servers for purposes of QoS and statistics gathering.
  28                 Writing into this file will change the name, reading outputs
  29                 currently set value.
  30
  31 What:           /sys/fs/lustre/jobid_var
  32 Date:           May 2015
  33 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  34 Description:
  35                 Control file for lustre "jobstats" functionality, write new
  36                 value from the list below to change the mode:
  37                 disable - disable job name reporting to the servers (default)
  38                 procname_uid - form the job name as the current running
  39                                command name and pid with a dot in between
  40                                e.g. dd.1253
  41                 nodelocal - use jobid_name value from above.
  42
  43 What:           /sys/fs/lustre/timeout
  44 Date:           June 2015
  45 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  46 Description:
  47                 Controls "lustre timeout" variable, also known as obd_timeout
  48                 in some old manual. In the past obd_timeout was of paramount
  49                 importance as the timeout value used everywhere and where
  50                 other timeouts were derived from. These days it's much less
  51                 important as network timeouts are mostly determined by
  52                 AT (adaptive timeouts).
  53                 Unit: seconds, default: 100
  54
  55 What:           /sys/fs/lustre/max_dirty_mb
  56 Date:           June 2015
  57 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  58 Description:
  59                 Controls total number of dirty cache (in megabytes) allowed
  60                 across all mounted lustre filesystems.
  61                 Since writeout of dirty pages in Lustre is somewhat expensive,
  62                 when you allow to many dirty pages, this might lead to
  63                 performance degradations as kernel tries to desperately
  64                 find some pages to free/writeout.
  65                 Default 1/2 RAM. Min value 4, max value 9/10 of RAM.
  66
  67 What:           /sys/fs/lustre/debug_peer_on_timeout
  68 Date:           June 2015
  69 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  70 Description:
  71                 Control if lnet debug information should be printed when
  72                 an RPC timeout occurs.
  73                 0 disabled (default)
  74                 1 enabled
  75
  76 What:           /sys/fs/lustre/dump_on_timeout
  77 Date:           June 2015
  78 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  79 Description:
  80                 Controls if Lustre debug log should be dumped when an RPC
  81                 timeout occurs. This is useful if yout debug buffer typically
  82                 rolls over by the time you notice RPC timeouts.
  83
  84 What:           /sys/fs/lustre/dump_on_eviction
  85 Date:           June 2015
  86 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  87 Description:
  88                 Controls if Lustre debug log should be dumped when an this
  89                 client is evicted from one of the servers.
  90                 This is useful if yout debug buffer typically rolls over
  91                  by the time you notice the eviction event.
  92
  93 What:           /sys/fs/lustre/at_min
  94 Date:           July 2015
  95 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
  96 Description:
  97                 Controls minimum adaptive timeout in seconds. If you encounter
  98                 a case where clients timeout due to server-reported processing
  99                 time being too short, you might consider increasing this value.
 100                 One common case of this if the underlying network has
 101                 unpredictable long delays.
 102                 Default: 0
 103
 104 What:           /sys/fs/lustre/at_max
 105 Date:           July 2015
 106 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 107 Description:
 108                 Controls maximum adaptive timeout in seconds. If at_max timeout
 109                 is reached for an RPC, the RPC will time out.
 110                 Some genuinuely slow network hardware might warrant increasing
 111                 this value.
 112                 Setting this value to 0 disables Adaptive Timeouts
 113                 functionality and old-style obd_timeout value is then used.
 114                 Default: 600
 115
 116 What:           /sys/fs/lustre/at_extra
 117 Date:           July 2015
 118 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 119 Description:
 120                 Controls how much extra time to request for unfinished requests
 121                 in processing in seconds. Normally a server-side parameter, it
 122                 is also used on the client for responses to various LDLM ASTs
 123                 that are handled with a special server thread on the client.
 124                 This is a way for the servers to ask the clients not to time
 125                 out the request that reached current servicing time estimate
 126                 yet and give it some more time.
 127                 Default: 30
 128
 129 What:           /sys/fs/lustre/at_early_margin
 130 Date:           July 2015
 131 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 132 Description:
 133                 Controls when to send the early reply for requests that are
 134                 about to timeout as an offset to the estimated service time in
 135                 seconds..
 136                 Default: 5
 137
 138 What:           /sys/fs/lustre/at_history
 139 Date:           July 2015
 140 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 141 Description:
 142                 Controls for how many seconds to remember slowest events
 143                 encountered by adaptive timeouts code.
 144                 Default: 600
 145
 146 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/blocksize
 147 Date:           May 2015
 148 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 149 Description:
 150                 Biggest blocksize on object storage server for this filesystem.
 151
 152 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/kbytestotal
 153 Date:           May 2015
 154 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 155 Description:
 156                 Shows total number of kilobytes of space on this filesystem
 157
 158 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/kbytesfree
 159 Date:           May 2015
 160 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 161 Description:
 162                 Shows total number of free kilobytes of space on this filesystem
 163
 164 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/kbytesavail
 165 Date:           May 2015
 166 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 167 Description:
 168                 Shows total number of free kilobytes of space on this filesystem
 169                 actually available for use (taking into account per-client
 170                 grants and filesystem reservations).
 171
 172 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/filestotal
 173 Date:           May 2015
 174 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 175 Description:
 176                 Shows total number of inodes on the filesystem.
 177
 178 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/filesfree
 179 Date:           May 2015
 180 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 181 Description:
 182                 Shows estimated number of free inodes on the filesystem
 183
 184 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/client_type
 185 Date:           May 2015
 186 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 187 Description:
 188                 Shows whenever this filesystem considers this client to be
 189                 compute cluster-local or remote. Remote clients have
 190                 additional uid/gid convrting logic applied.
 191
 192 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/fstype
 193 Date:           May 2015
 194 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 195 Description:
 196                 Shows filesystem type of the filesystem
 197
 198 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/uuid
 199 Date:           May 2015
 200 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 201 Description:
 202                 Shows this filesystem superblock uuid
 203
 204 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/max_read_ahead_mb
 205 Date:           May 2015
 206 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 207 Description:
 208                 Sets maximum number of megabytes in system memory to be
 209                 given to read-ahead cache.
 210
 211 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/max_read_ahead_per_file_mb
 212 Date:           May 2015
 213 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 214 Description:
 215                 Sets maximum number of megabytes to read-ahead for a single file
 216
 217 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/max_read_ahead_whole_mb
 218 Date:           May 2015
 219 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 220 Description:
 221                 For small reads, how many megabytes to actually request from
 222                 the server as initial read-ahead.
 223
 224 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/checksum_pages
 225 Date:           May 2015
 226 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 227 Description:
 228                 Enables or disables per-page checksum at llite layer, before
 229                 the pages are actually given to lower level for network transfer
 230
 231 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/stats_track_pid
 232 Date:           May 2015
 233 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 234 Description:
 235                 Limit Lustre vfs operations gathering to just a single pid.
 236                 0 to track everything.
 237
 238 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/stats_track_ppid
 239 Date:           May 2015
 240 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 241 Description:
 242                 Limit Lustre vfs operations gathering to just a single ppid.
 243                 0 to track everything.
 244
 245 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/stats_track_gid
 246 Date:           May 2015
 247 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 248 Description:
 249                 Limit Lustre vfs operations gathering to just a single gid.
 250                 0 to track everything.
 251
 252 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/statahead_max
 253 Date:           May 2015
 254 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 255 Description:
 256                 Controls maximum number of statahead requests to send when
 257                 sequential readdir+stat pattern is detected.
 258
 259 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/statahead_agl
 260 Date:           May 2015
 261 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 262 Description:
 263                 Controls if AGL (async glimpse ahead - obtain object information
 264                 from OSTs in parallel with MDS during statahead) should be
 265                 enabled or disabled.
 266                 0 to disable, 1 to enable.
 267
 268 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/lazystatfs
 269 Date:           May 2015
 270 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 271 Description:
 272                 Controls statfs(2) behaviour in the face of down servers.
 273                 If 0, always wait for all servers to come online,
 274                 if 1, ignote inactive servers.
 275
 276 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/max_easize
 277 Date:           May 2015
 278 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 279 Description:
 280                 Shows maximum number of bytes file striping data could be
 281                 in current configuration of storage.
 282
 283 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/default_easize
 284 Date:           May 2015
 285 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 286 Description:
 287                 Shows maximum observed file striping data seen by this
 288                 filesystem client instance.
 289
 290 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/xattr_cache
 291 Date:           May 2015
 292 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 293 Description:
 294                 Controls extended attributes client-side cache.
 295                 1 to enable, 0 to disable.
 296
 297 What:           /sys/fs/lustre/llite/<fsname>-<uuid>/unstable_stats
 298 Date:           Apr 2016
 299 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 300 Description:
 301                 Shows number of pages that were sent and acknowledged by
 302                 server but were not yet committed and therefore still
 303                 pinned in client memory even though no longer dirty.
 304
 305 What:           /sys/fs/lustre/ldlm/cancel_unused_locks_before_replay
 306 Date:           May 2015
 307 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 308 Description:
 309                 Controls if client should replay unused locks during recovery
 310                 If a client tends to have a lot of unused locks in LRU,
 311                 recovery times might become prolonged.
 312                 1 - just locally cancel unused locks (default)
 313                 0 - replay unused locks.
 314
 315 What:           /sys/fs/lustre/ldlm/namespaces/<name>/resource_count
 316 Date:           May 2015
 317 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 318 Description:
 319                 Displays number of lock resources (objects on which individual
 320                 locks are taken) currently allocated in this namespace.
 321
 322 What:           /sys/fs/lustre/ldlm/namespaces/<name>/lock_count
 323 Date:           May 2015
 324 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 325 Description:
 326                 Displays number or locks allocated in this namespace.
 327
 328 What:           /sys/fs/lustre/ldlm/namespaces/<name>/lru_size
 329 Date:           May 2015
 330 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 331 Description:
 332                 Controls and displays LRU size limit for unused locks for this
 333                 namespace.
 334                 0 - LRU size is unlimited, controlled by server resources
 335                 positive number - number of locks to allow in lock LRU list
 336
 337 What:           /sys/fs/lustre/ldlm/namespaces/<name>/lock_unused_count
 338 Date:           May 2015
 339 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 340 Description:
 341                 Display number of locks currently sitting in the LRU list
 342                 of this namespace
 343
 344 What:           /sys/fs/lustre/ldlm/namespaces/<name>/lru_max_age
 345 Date:           May 2015
 346 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 347 Description:
 348                 Maximum number of milliseconds a lock could sit in LRU list
 349                 before client would voluntarily cancel it as unused.
 350
 351 What:           /sys/fs/lustre/ldlm/namespaces/<name>/early_lock_cancel
 352 Date:           May 2015
 353 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 354 Description:
 355                 Controls "early lock cancellation" feature on this namespace
 356                 if supported by the server.
 357                 When enabled, tries to preemtively cancel locks that would be
 358                 cancelled by verious operations and bundle the cancellation
 359                 requests in the same RPC as the main operation, which results
 360                 in significant speedups due to reduced lock-pingpong RPCs.
 361                 0 - disabled
 362                 1 - enabled (default)
 363
 364 What:           /sys/fs/lustre/ldlm/namespaces/<name>/pool/granted
 365 Date:           May 2015
 366 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 367 Description:
 368                 Displays number of granted locks in this namespace
 369
 370 What:           /sys/fs/lustre/ldlm/namespaces/<name>/pool/grant_rate
 371 Date:           May 2015
 372 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 373 Description:
 374                 Number of granted locks in this namespace during last
 375                 time interval
 376
 377 What:           /sys/fs/lustre/ldlm/namespaces/<name>/pool/cancel_rate
 378 Date:           May 2015
 379 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 380 Description:
 381                 Number of lock cancellations in this namespace during
 382                 last time interval
 383
 384 What:           /sys/fs/lustre/ldlm/namespaces/<name>/pool/grant_speed
 385 Date:           May 2015
 386 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 387 Description:
 388                 Calculated speed of lock granting (grant_rate - cancel_rate)
 389                 in this namespace
 390
 391 What:           /sys/fs/lustre/ldlm/namespaces/<name>/pool/grant_plan
 392 Date:           May 2015
 393 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 394 Description:
 395                 Estimated number of locks to be granted in the next time
 396                 interval in this namespace
 397
 398 What:           /sys/fs/lustre/ldlm/namespaces/<name>/pool/limit
 399 Date:           May 2015
 400 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 401 Description:
 402                 Controls number of allowed locks in this pool.
 403                 When lru_size is 0, this is the actual limit then.
 404
 405 What:           /sys/fs/lustre/ldlm/namespaces/<name>/pool/lock_volume_factor
 406 Date:           May 2015
 407 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 408 Description:
 409                 Multiplier for all lock volume calculations above.
 410                 Default is 1. Increase to make the client to more agressively
 411                 clean it's lock LRU list for this namespace.
 412
 413 What:           /sys/fs/lustre/ldlm/namespaces/<name>/pool/server_lock_volume
 414 Date:           May 2015
 415 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 416 Description:
 417                 Calculated server lock volume.
 418
 419 What:           /sys/fs/lustre/ldlm/namespaces/<name>/pool/recalc_period
 420 Date:           May 2015
 421 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 422 Description:
 423                 Controls length of time between recalculation of above
 424                 values (in seconds).
 425
 426 What:           /sys/fs/lustre/ldlm/services/ldlm_cbd/threads_min
 427 Date:           May 2015
 428 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 429 Description:
 430                 Controls minimum number of ldlm callback threads to start.
 431
 432 What:           /sys/fs/lustre/ldlm/services/ldlm_cbd/threads_max
 433 Date:           May 2015
 434 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 435 Description:
 436                 Controls maximum number of ldlm callback threads to start.
 437
 438 What:           /sys/fs/lustre/ldlm/services/ldlm_cbd/threads_started
 439 Date:           May 2015
 440 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 441 Description:
 442                 Shows actual number of ldlm callback threads running.
 443
 444 What:           /sys/fs/lustre/ldlm/services/ldlm_cbd/high_priority_ratio
 445 Date:           May 2015
 446 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 447 Description:
 448                 Controls what percentage of ldlm callback threads is dedicated
 449                 to "high priority" incoming requests.
 450
 451 What:           /sys/fs/lustre/{obdtype}/{connection_name}/blocksize
 452 Date:           May 2015
 453 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 454 Description:
 455                 Blocksize on backend filesystem for service behind this obd
 456                 device (or biggest blocksize for compound devices like lov
 457                 and lmv)
 458
 459 What:           /sys/fs/lustre/{obdtype}/{connection_name}/kbytestotal
 460 Date:           May 2015
 461 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 462 Description:
 463                 Total number of kilobytes of space on backend filesystem
 464                 for service behind this obd (or total amount for compound
 465                 devices like lov lmv)
 466
 467 What:           /sys/fs/lustre/{obdtype}/{connection_name}/kbytesfree
 468 Date:           May 2015
 469 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 470 Description:
 471                 Number of free kilobytes on backend filesystem for service
 472                 behind this obd (or total amount for compound devices
 473                 like lov lmv)
 474
 475 What:           /sys/fs/lustre/{obdtype}/{connection_name}/kbytesavail
 476 Date:           May 2015
 477 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 478 Description:
 479                 Number of kilobytes of free space on backend filesystem
 480                 for service behind this obd (or total amount for compound
 481                 devices like lov lmv) that is actually available for use
 482                 (taking into account per-client and filesystem reservations).
 483
 484 What:           /sys/fs/lustre/{obdtype}/{connection_name}/filestotal
 485 Date:           May 2015
 486 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 487 Description:
 488                 Number of inodes on backend filesystem for service behind this
 489                 obd.
 490
 491 What:           /sys/fs/lustre/{obdtype}/{connection_name}/filesfree
 492 Date:           May 2015
 493 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 494 Description:
 495                 Number of free inodes on backend filesystem for service
 496                 behind this obd.
 497
 498 What:           /sys/fs/lustre/mdc/{connection_name}/max_pages_per_rpc
 499 Date:           May 2015
 500 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 501 Description:
 502                 Maximum number of readdir pages to fit into a single readdir
 503                 RPC.
 504
 505 What:           /sys/fs/lustre/{mdc,osc}/{connection_name}/max_rpcs_in_flight
 506 Date:           May 2015
 507 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 508 Description:
 509                 Maximum number of parallel RPCs on the wire to allow on
 510                 this connection. Increasing this number would help on higher
 511                 latency links, but has a chance of overloading a server
 512                 if you have too many clients like this.
 513                 Default: 8
 514
 515 What:           /sys/fs/lustre/osc/{connection_name}/max_pages_per_rpc
 516 Date:           May 2015
 517 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 518 Description:
 519                 Maximum number of pages to fit into a single RPC.
 520                 Typically bigger RPCs allow for better performance.
 521                 Default: however many pages to form 1M of data (256 pages
 522                 for 4K page sized platforms)
 523
 524 What:           /sys/fs/lustre/osc/{connection_name}/active
 525 Date:           May 2015
 526 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 527 Description:
 528                 Controls accessibility of this connection. If set to 0,
 529                 fail all accesses immediately.
 530
 531 What:           /sys/fs/lustre/osc/{connection_name}/checksums
 532 Date:           May 2015
 533 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 534 Description:
 535                 Controls whenever to checksum bulk RPC data over the wire
 536                 to this target.
 537                 1: enable (default) ; 0: disable
 538
 539 What:           /sys/fs/lustre/osc/{connection_name}/contention_seconds
 540 Date:           May 2015
 541 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 542 Description:
 543                 Controls for how long to consider a file contended once
 544                 indicated as such by the server.
 545                 When a file is considered contended, all operations switch to
 546                 synchronous lockless mode to avoid cache and lock pingpong.
 547
 548 What:           /sys/fs/lustre/osc/{connection_name}/cur_dirty_bytes
 549 Date:           May 2015
 550 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 551 Description:
 552                 Displays how many dirty bytes is presently in the cache for this
 553                 target.
 554
 555 What:           /sys/fs/lustre/osc/{connection_name}/cur_grant_bytes
 556 Date:           May 2015
 557 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 558 Description:
 559                 Shows how many bytes we have as a "dirty cache" grant from the
 560                 server. Writing a value smaller than shown allows to release
 561                 some grant back to the server.
 562                 Dirty cache grant is a way Lustre ensures that cached successful
 563                 writes on client do not end up discarded by the server due to
 564                 lack of space later on.
 565
 566 What:           /sys/fs/lustre/osc/{connection_name}/cur_lost_grant_bytes
 567 Date:           May 2015
 568 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 569 Description:
 570                 Shows how many granted bytes were released to the server due
 571                 to lack of write activity on this client.
 572
 573 What:           /sys/fs/lustre/osc/{connection_name}/grant_shrink_interval
 574 Date:           May 2015
 575 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 576 Description:
 577                 Number of seconds with no write activity for this target
 578                 to start releasing dirty grant back to the server.
 579
 580 What:           /sys/fs/lustre/osc/{connection_name}/destroys_in_flight
 581 Date:           May 2015
 582 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 583 Description:
 584                 Number of DESTROY RPCs currently in flight to this target.
 585
 586 What:           /sys/fs/lustre/osc/{connection_name}/lockless_truncate
 587 Date:           May 2015
 588 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 589 Description:
 590                 Controls whether lockless truncate RPCs are allowed to this
 591                 target.
 592                 Lockless truncate causes server to perform the locking which
 593                 is beneficial if the truncate is not followed by a write
 594                 immediately.
 595                 1: enable ; 0: disable (default)
 596
 597 What:           /sys/fs/lustre/osc/{connection_name}/max_dirty_mb
 598 Date:           May 2015
 599 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 600 Description:
 601                 Controls how much dirty data this client can accumulate
 602                 for this target. This is orthogonal to dirty grant and is
 603                 a hard limit even if the server would allow a bigger dirty
 604                 cache.
 605                 While allowing higher dirty cache is beneficial for write
 606                 performance, flushing write cache takes longer and as such
 607                 the node might be more prone to OOMs.
 608                 Having this value set too low might result in not being able
 609                 to sent too many parallel WRITE RPCs.
 610                 Default: 32
 611
 612 What:           /sys/fs/lustre/osc/{connection_name}/resend_count
 613 Date:           May 2015
 614 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 615 Description:
 616                 Controls how many times to try and resend RPCs to this target
 617                 that failed with "recoverable" status, such as EAGAIN,
 618                 ENOMEM.
 619
 620 What:           /sys/fs/lustre/lov/{connection_name}/numobd
 621 Date:           May 2015
 622 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 623 Description:
 624                 Number of OSC targets managed by this LOV instance.
 625
 626 What:           /sys/fs/lustre/lov/{connection_name}/activeobd
 627 Date:           May 2015
 628 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 629 Description:
 630                 Number of OSC targets managed by this LOV instance that are
 631                 actually active.
 632
 633 What:           /sys/fs/lustre/lmv/{connection_name}/numobd
 634 Date:           May 2015
 635 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 636 Description:
 637                 Number of MDC targets managed by this LMV instance.
 638
 639 What:           /sys/fs/lustre/lmv/{connection_name}/activeobd
 640 Date:           May 2015
 641 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 642 Description:
 643                 Number of MDC targets managed by this LMV instance that are
 644                 actually active.
 645
 646 What:           /sys/fs/lustre/lmv/{connection_name}/placement
 647 Date:           May 2015
 648 Contact:        "Oleg Drokin" <oleg.drokin@intel.com>
 649 Description:
 650                 Determines policy of inode placement in case of multiple
 651                 metadata servers:
 652                 CHAR - based on a hash of the file name used at creation time
 653                        (Default)
 654                 NID - based on a hash of creating client network id.