[ceph.git] / ceph / doc / cephfs / mds-config-ref.rst

======================
 MDS Config Reference
======================

``mon force standby active`` 

:Description: If ``true`` monitors force standby-replay to be active. Set
              under ``[mon]`` or ``[global]``.

:Type: Boolean
:Default: ``true`` 

``mds cache memory limit``

:Description: The memory limit the MDS should enforce for its cache.
              Administrators should use this instead of ``mds cache size``.
:Type:  64-bit Integer Unsigned
:Default: ``1073741824``

``mds cache reservation``

:Description: The cache reservation (memory or inodes) for the MDS cache to maintain.
              Once the MDS begins dipping into its reservation, it will recall
              client state until its cache size shrinks to restore the
              reservation.
:Type:  Float
:Default: ``0.05``

``mds cache size``

:Description: The number of inodes to cache. A value of 0 indicates an
              unlimited number. It is recommended to use
              ``mds_cache_memory_limit`` to limit the amount of memory the MDS
              cache uses.
:Type:  32-bit Integer
:Default: ``0``

``mds cache mid``

:Description: The insertion point for new items in the cache LRU 
              (from the top).

:Type:  Float
:Default: ``0.7``


``mds dir commit ratio``

:Description: The fraction of directory that is dirty before Ceph commits using 
              a full update (instead of partial update).

:Type:  Float
:Default: ``0.5``


``mds dir max commit size``

:Description: The maximum size of a directory update before Ceph breaks it into 
              smaller transactions) (MB).
              
:Type:  32-bit Integer
:Default: ``90``


``mds decay halflife``

:Description: The half-life of MDS cache temperature.
:Type:  Float
:Default: ``5``

``mds beacon interval``

:Description: The frequency (in seconds) of beacon messages sent 
              to the monitor.

:Type:  Float
:Default: ``4``


``mds beacon grace``

:Description: The interval without beacons before Ceph declares an MDS laggy 
              (and possibly replace it).
              
:Type:  Float
:Default: ``15``


``mds blacklist interval``

:Description: The blacklist duration for failed MDSs in the OSD map. Note,
              this controls how long failed MDS daemons will stay in the
              OSDMap blacklist. It has no effect on how long something is
              blacklisted when the administrator blacklists it manually. For
              example, ``ceph osd blacklist add`` will still use the default
              blacklist time.
:Type:  Float
:Default: ``24.0*60.0``


``mds reconnect timeout``

:Description: The interval (in seconds) to wait for clients to reconnect 
              during MDS restart.

:Type:  Float
:Default: ``45``


``mds tick interval``

:Description: How frequently the MDS performs internal periodic tasks.
:Type:  Float
:Default: ``5``


``mds dirstat min interval``

:Description: The minimum interval (in seconds) to try to avoid propagating 
              recursive stats up the tree.
              
:Type:  Float
:Default: ``1``

``mds scatter nudge interval``

:Description: How quickly dirstat changes propagate up.
:Type:  Float
:Default: ``5``


``mds client prealloc inos``

:Description: The number of inode numbers to preallocate per client session.
:Type:  32-bit Integer
:Default: ``1000``


``mds early reply``

:Description: Determines whether the MDS should allow clients to see request 
              results before they commit to the journal.

:Type:  Boolean
:Default: ``true``


``mds default dir hash``

:Description: The function to use for hashing files across directory fragments.
:Type:  32-bit Integer
:Default: ``2`` (i.e., rjenkins)


``mds log skip corrupt events``

:Description: Determines whether the MDS should try to skip corrupt journal 
              events during journal replay.
              
:Type:  Boolean
:Default:  ``false``


``mds log max events``

:Description: The maximum events in the journal before we initiate trimming.
              Set to ``-1`` to disable limits.
              
:Type:  32-bit Integer
:Default: ``-1``


``mds log max segments``

:Description: The maximum number of segments (objects) in the journal before 
              we initiate trimming. Set to ``-1`` to disable limits.

:Type:  32-bit Integer
:Default: ``30``


``mds log max expiring``

:Description: The maximum number of segments to expire in parallels
:Type:  32-bit Integer
:Default: ``20``


``mds log eopen size``

:Description: The maximum number of inodes in an EOpen event.
:Type:  32-bit Integer
:Default: ``100``


``mds bal sample interval``

:Description: Determines how frequently to sample directory temperature 
              (for fragmentation decisions).
              
:Type:  Float
:Default: ``3``


``mds bal replicate threshold``

:Description: The maximum temperature before Ceph attempts to replicate 
              metadata to other nodes.
              
:Type:  Float
:Default: ``8000``


``mds bal unreplicate threshold``

:Description: The minimum temperature before Ceph stops replicating 
              metadata to other nodes.
              
:Type:  Float
:Default: ``0``


``mds bal split size``

:Description: The maximum directory size before the MDS will split a directory 
              fragment into smaller bits.
              
:Type:  32-bit Integer
:Default: ``10000``


``mds bal split rd``

:Description: The maximum directory read temperature before Ceph splits 
              a directory fragment.
              
:Type:  Float
:Default: ``25000``


``mds bal split wr``

:Description: The maximum directory write temperature before Ceph splits 
              a directory fragment.
              
:Type:  Float
:Default: ``10000``


``mds bal split bits``

:Description: The number of bits by which to split a directory fragment.
:Type:  32-bit Integer
:Default: ``3``


``mds bal merge size``

:Description: The minimum directory size before Ceph tries to merge 
              adjacent directory fragments.
              
:Type:  32-bit Integer
:Default: ``50``


``mds bal interval``

:Description: The frequency (in seconds) of workload exchanges between MDSs.
:Type:  32-bit Integer
:Default: ``10``


``mds bal fragment interval``

:Description: The delay (in seconds) between a fragment being eligible for split
              or merge and executing the fragmentation change.
:Type:  32-bit Integer
:Default: ``5``


``mds bal fragment fast factor``

:Description: The ratio by which frags may exceed the split size before
              a split is executed immediately (skipping the fragment interval)
:Type:  Float
:Default: ``1.5``

``mds bal fragment size max``

:Description: The maximum size of a fragment before any new entries
              are rejected with ENOSPC.
:Type:  32-bit Integer
:Default: ``100000``

``mds bal idle threshold``

:Description: The minimum temperature before Ceph migrates a subtree 
              back to its parent.
              
:Type:  Float
:Default: ``0``


``mds bal max``

:Description: The number of iterations to run balancer before Ceph stops. 
              (used for testing purposes only)

:Type:  32-bit Integer
:Default: ``-1``


``mds bal max until``

:Description: The number of seconds to run balancer before Ceph stops. 
              (used for testing purposes only)

:Type:  32-bit Integer
:Default: ``-1``


``mds bal mode``

:Description: The method for calculating MDS load. 

              - ``0`` = Hybrid.
              - ``1`` = Request rate and latency. 
              - ``2`` = CPU load.
              
:Type:  32-bit Integer
:Default: ``0``


``mds bal min rebalance``

:Description: The minimum subtree temperature before Ceph migrates.
:Type:  Float
:Default: ``0.1``


``mds bal min start``

:Description: The minimum subtree temperature before Ceph searches a subtree.
:Type:  Float
:Default: ``0.2``


``mds bal need min``

:Description: The minimum fraction of target subtree size to accept.
:Type:  Float
:Default: ``0.8``


``mds bal need max``

:Description: The maximum fraction of target subtree size to accept.
:Type:  Float
:Default: ``1.2``


``mds bal midchunk``

:Description: Ceph will migrate any subtree that is larger than this fraction 
              of the target subtree size.
              
:Type:  Float
:Default: ``0.3``


``mds bal minchunk``

:Description: Ceph will ignore any subtree that is smaller than this fraction 
              of the target subtree size.
              
:Type:  Float
:Default: ``0.001``


``mds bal target removal min``

:Description: The minimum number of balancer iterations before Ceph removes
              an old MDS target from the MDS map.
              
:Type:  32-bit Integer
:Default: ``5``


``mds bal target removal max``

:Description: The maximum number of balancer iteration before Ceph removes 
              an old MDS target from the MDS map.
              
:Type:  32-bit Integer
:Default: ``10``


``mds replay interval``

:Description: The journal poll interval when in standby-replay mode.
              ("hot standby")
              
:Type:  Float
:Default: ``1``


``mds shutdown check``

:Description: The interval for polling the cache during MDS shutdown.
:Type:  32-bit Integer
:Default: ``0``


``mds thrash exports``

:Description: Ceph will randomly export subtrees between nodes (testing only).
:Type:  32-bit Integer
:Default: ``0``


``mds thrash fragments``

:Description: Ceph will randomly fragment or merge directories.
:Type:  32-bit Integer
:Default: ``0``


``mds dump cache on map``

:Description: Ceph will dump the MDS cache contents to a file on each MDSMap.
:Type:  Boolean
:Default:  ``false``


``mds dump cache after rejoin``

:Description: Ceph will dump MDS cache contents to a file after 
              rejoining the cache (during recovery).
              
:Type:  Boolean
:Default:  ``false``


``mds verify scatter``

:Description: Ceph will assert that various scatter/gather invariants 
              are ``true`` (developers only).
              
:Type:  Boolean
:Default:  ``false``


``mds debug scatterstat``

:Description: Ceph will assert that various recursive stat invariants 
              are ``true`` (for developers only).
              
:Type:  Boolean
:Default:  ``false``


``mds debug frag``

:Description: Ceph will verify directory fragmentation invariants 
              when convenient (developers only).
              
:Type:  Boolean
:Default:  ``false``


``mds debug auth pins``

:Description: The debug auth pin invariants (for developers only).
:Type:  Boolean
:Default:  ``false``


``mds debug subtrees``

:Description: The debug subtree invariants (for developers only).
:Type:  Boolean
:Default:  ``false``


``mds kill mdstable at``

:Description: Ceph will inject MDS failure in MDSTable code 
              (for developers only).
              
:Type:  32-bit Integer
:Default: ``0``


``mds kill export at``

:Description: Ceph will inject MDS failure in the subtree export code 
              (for developers only).
              
:Type:  32-bit Integer
:Default: ``0``


``mds kill import at``

:Description: Ceph will inject MDS failure in the subtree import code 
              (for developers only).
              
:Type:  32-bit Integer
:Default: ``0``


``mds kill link at``

:Description: Ceph will inject MDS failure in hard link code 
              (for developers only).
              
:Type:  32-bit Integer
:Default: ``0``


``mds kill rename at``

:Description: Ceph will inject MDS failure in the rename code 
              (for developers only).
              
:Type:  32-bit Integer
:Default: ``0``


``mds wipe sessions``

:Description: Ceph will delete all client sessions on startup 
              (for testing only).
              
:Type:  Boolean
:Default: ``false``


``mds wipe ino prealloc``

:Description: Ceph will delete ino preallocation metadata on startup 
              (for testing only).
              
:Type:  Boolean
:Default: ``false``


``mds skip ino``

:Description: The number of inode numbers to skip on startup 
              (for testing only).
              
:Type:  32-bit Integer
:Default: ``0``


``mds standby for name``

:Description: An MDS daemon will standby for another MDS daemon of the name 
              specified in this setting.

:Type:  String
:Default: N/A


``mds standby for rank``

:Description: An MDS daemon will standby for an MDS daemon of this rank. 
:Type:  32-bit Integer
:Default: ``-1``


``mds standby replay``

:Description: Determines whether a ``ceph-mds`` daemon should poll and replay 
              the log of an active MDS (hot standby).
              
:Type:  Boolean
:Default:  ``false``


``mds min caps per client``

:Description: Set the minimum number of capabilities a client may hold.
:Type: Integer
:Default: ``100``


``mds max ratio caps per client``

:Description: Set the maximum ratio of current caps that may be recalled during MDS cache pressure.
:Type: Float
:Default: ``0.8``
Commit	Line	Data
7c673cae FG	1	======================
	2	MDS Config Reference
	3	======================
	4
	5	``mon force standby active``
	6
	7	:Description: If ``true`` monitors force standby-replay to be active. Set
	8	under ``[mon]`` or ``[global]``.
	9
	10	:Type: Boolean
	11	:Default: ``true``
	12
181888fb FG	13	``mds cache memory limit``
	14
	15	:Description: The memory limit the MDS should enforce for its cache.
	16	Administrators should use this instead of ``mds cache size``.
	17	:Type: 64-bit Integer Unsigned
	18	:Default: ``1073741824``
	19
	20	``mds cache reservation``
	21
	22	:Description: The cache reservation (memory or inodes) for the MDS cache to maintain.
	23	Once the MDS begins dipping into its reservation, it will recall
	24	client state until its cache size shrinks to restore the
	25	reservation.
	26	:Type: Float
	27	:Default: ``0.05``
7c673cae FG	28
	29	``mds cache size``
	30
181888fb FG	31	:Description: The number of inodes to cache. A value of 0 indicates an
	32	unlimited number. It is recommended to use
	33	``mds_cache_memory_limit`` to limit the amount of memory the MDS
	34	cache uses.
7c673cae	35	:Type: 32-bit Integer
181888fb	36	:Default: ``0``
7c673cae FG	37
	38	``mds cache mid``
	39
	40	:Description: The insertion point for new items in the cache LRU
	41	(from the top).
	42
	43	:Type: Float
	44	:Default: ``0.7``
	45
	46
	47	``mds dir commit ratio``
	48
	49	:Description: The fraction of directory that is dirty before Ceph commits using
	50	a full update (instead of partial update).
	51
	52	:Type: Float
	53	:Default: ``0.5``
	54
	55
	56	``mds dir max commit size``
	57
	58	:Description: The maximum size of a directory update before Ceph breaks it into
	59	smaller transactions) (MB).
	60
	61	:Type: 32-bit Integer
	62	:Default: ``90``
	63
	64
	65	``mds decay halflife``
	66
	67	:Description: The half-life of MDS cache temperature.
	68	:Type: Float
	69	:Default: ``5``
	70
	71	``mds beacon interval``
	72
	73	:Description: The frequency (in seconds) of beacon messages sent
	74	to the monitor.
	75
	76	:Type: Float
	77	:Default: ``4``
	78
	79
	80	``mds beacon grace``
	81
	82	:Description: The interval without beacons before Ceph declares an MDS laggy
	83	(and possibly replace it).
	84
	85	:Type: Float
	86	:Default: ``15``
	87
	88
	89	``mds blacklist interval``
	90
11fdf7f2 TL	91	:Description: The blacklist duration for failed MDSs in the OSD map. Note,
	92	this controls how long failed MDS daemons will stay in the
	93	OSDMap blacklist. It has no effect on how long something is
	94	blacklisted when the administrator blacklists it manually. For
	95	example, ``ceph osd blacklist add`` will still use the default
	96	blacklist time.
7c673cae FG	97	:Type: Float
	98	:Default: ``24.0*60.0``
	99
	100
7c673cae FG	101	``mds reconnect timeout``
	102
	103	:Description: The interval (in seconds) to wait for clients to reconnect
	104	during MDS restart.
	105
	106	:Type: Float
	107	:Default: ``45``
	108
	109
	110	``mds tick interval``
	111
	112	:Description: How frequently the MDS performs internal periodic tasks.
	113	:Type: Float
	114	:Default: ``5``
	115
	116
	117	``mds dirstat min interval``
	118
	119	:Description: The minimum interval (in seconds) to try to avoid propagating
	120	recursive stats up the tree.
	121
	122	:Type: Float
	123	:Default: ``1``
	124
	125	``mds scatter nudge interval``
	126
	127	:Description: How quickly dirstat changes propagate up.
	128	:Type: Float
	129	:Default: ``5``
	130
	131
	132	``mds client prealloc inos``
	133
	134	:Description: The number of inode numbers to preallocate per client session.
	135	:Type: 32-bit Integer
	136	:Default: ``1000``
	137
	138
	139	``mds early reply``
	140
	141	:Description: Determines whether the MDS should allow clients to see request
	142	results before they commit to the journal.
	143
	144	:Type: Boolean
	145	:Default: ``true``
	146
	147
7c673cae FG	148	``mds default dir hash``
	149
	150	:Description: The function to use for hashing files across directory fragments.
	151	:Type: 32-bit Integer
	152	:Default: ``2`` (i.e., rjenkins)
	153
	154
	155	``mds log skip corrupt events``
	156
	157	:Description: Determines whether the MDS should try to skip corrupt journal
	158	events during journal replay.
	159
	160	:Type: Boolean
	161	:Default: ``false``
	162
	163
	164	``mds log max events``
	165
	166	:Description: The maximum events in the journal before we initiate trimming.
	167	Set to ``-1`` to disable limits.
	168
	169	:Type: 32-bit Integer
	170	:Default: ``-1``
	171
	172
	173	``mds log max segments``
	174
	175	:Description: The maximum number of segments (objects) in the journal before
	176	we initiate trimming. Set to ``-1`` to disable limits.
	177
	178	:Type: 32-bit Integer
	179	:Default: ``30``
	180
	181
	182	``mds log max expiring``
	183
	184	:Description: The maximum number of segments to expire in parallels
	185	:Type: 32-bit Integer
	186	:Default: ``20``
	187
	188
	189	``mds log eopen size``
	190
	191	:Description: The maximum number of inodes in an EOpen event.
	192	:Type: 32-bit Integer
	193	:Default: ``100``
	194
	195
	196	``mds bal sample interval``
	197
	198	:Description: Determines how frequently to sample directory temperature
	199	(for fragmentation decisions).
	200
	201	:Type: Float
	202	:Default: ``3``
	203
	204
	205	``mds bal replicate threshold``
	206
	207	:Description: The maximum temperature before Ceph attempts to replicate
	208	metadata to other nodes.
	209
	210	:Type: Float
	211	:Default: ``8000``
212
213
214	``mds bal unreplicate threshold``
215
216	:Description: The minimum temperature before Ceph stops replicating
217	metadata to other nodes.
218
219	:Type: Float
220	:Default: ``0``
221
222
7c673cae FG	223	``mds bal split size``
	224
	225	:Description: The maximum directory size before the MDS will split a directory
	226	fragment into smaller bits.
	227
	228	:Type: 32-bit Integer
	229	:Default: ``10000``
	230
	231
	232	``mds bal split rd``
	233
	234	:Description: The maximum directory read temperature before Ceph splits
	235	a directory fragment.
	236
	237	:Type: Float
	238	:Default: ``25000``
	239
	240
	241	``mds bal split wr``
	242
	243	:Description: The maximum directory write temperature before Ceph splits
	244	a directory fragment.
	245
	246	:Type: Float
	247	:Default: ``10000``
	248
	249
	250	``mds bal split bits``
	251
	252	:Description: The number of bits by which to split a directory fragment.
	253	:Type: 32-bit Integer
	254	:Default: ``3``
	255
	256
	257	``mds bal merge size``
	258
	259	:Description: The minimum directory size before Ceph tries to merge
	260	adjacent directory fragments.
	261
	262	:Type: 32-bit Integer
	263	:Default: ``50``
	264
	265
	266	``mds bal interval``
	267
	268	:Description: The frequency (in seconds) of workload exchanges between MDSs.
	269	:Type: 32-bit Integer
	270	:Default: ``10``
	271
	272
	273	``mds bal fragment interval``
	274
11fdf7f2	275	:Description: The delay (in seconds) between a fragment being eligible for split
7c673cae FG	276	or merge and executing the fragmentation change.
	277	:Type: 32-bit Integer
	278	:Default: ``5``
	279
	280
	281	``mds bal fragment fast factor``
	282
	283	:Description: The ratio by which frags may exceed the split size before
	284	a split is executed immediately (skipping the fragment interval)
	285	:Type: Float
	286	:Default: ``1.5``
	287
	288	``mds bal fragment size max``
	289
	290	:Description: The maximum size of a fragment before any new entries
	291	are rejected with ENOSPC.
	292	:Type: 32-bit Integer
	293	:Default: ``100000``
	294
	295	``mds bal idle threshold``
	296
	297	:Description: The minimum temperature before Ceph migrates a subtree
	298	back to its parent.
	299
	300	:Type: Float
	301	:Default: ``0``
	302
	303
	304	``mds bal max``
	305
	306	:Description: The number of iterations to run balancer before Ceph stops.
	307	(used for testing purposes only)
	308
	309	:Type: 32-bit Integer
	310	:Default: ``-1``
	311
	312
	313	``mds bal max until``
	314
	315	:Description: The number of seconds to run balancer before Ceph stops.
	316	(used for testing purposes only)
	317
	318	:Type: 32-bit Integer
	319	:Default: ``-1``
	320
	321
	322	``mds bal mode``
	323
	324	:Description: The method for calculating MDS load.
	325
	326	- ``0`` = Hybrid.
	327	- ``1`` = Request rate and latency.
	328	- ``2`` = CPU load.
	329
	330	:Type: 32-bit Integer
	331	:Default: ``0``
	332
	333
	334	``mds bal min rebalance``
	335
	336	:Description: The minimum subtree temperature before Ceph migrates.
	337	:Type: Float
	338	:Default: ``0.1``
	339
340
341	``mds bal min start``
342
343	:Description: The minimum subtree temperature before Ceph searches a subtree.
344	:Type: Float
345	:Default: ``0.2``
346
347
348	``mds bal need min``
349
350	:Description: The minimum fraction of target subtree size to accept.
351	:Type: Float
352	:Default: ``0.8``
353
354
355	``mds bal need max``
356
357	:Description: The maximum fraction of target subtree size to accept.
358	:Type: Float
359	:Default: ``1.2``
360
361
362	``mds bal midchunk``
363
364	:Description: Ceph will migrate any subtree that is larger than this fraction
365	of the target subtree size.
366
367	:Type: Float
368	:Default: ``0.3``
369
370
371	``mds bal minchunk``
372
373	:Description: Ceph will ignore any subtree that is smaller than this fraction
374	of the target subtree size.
375
376	:Type: Float
377	:Default: ``0.001``
378
379
380	``mds bal target removal min``
381
382	:Description: The minimum number of balancer iterations before Ceph removes
383	an old MDS target from the MDS map.
384
385	:Type: 32-bit Integer
386	:Default: ``5``
387
388
389	``mds bal target removal max``
390
391	:Description: The maximum number of balancer iteration before Ceph removes
392	an old MDS target from the MDS map.
393
394	:Type: 32-bit Integer
395	:Default: ``10``
396
397
398	``mds replay interval``
399
400	:Description: The journal poll interval when in standby-replay mode.
401	("hot standby")
402
403	:Type: Float
404	:Default: ``1``
405
406
407	``mds shutdown check``
408
409	:Description: The interval for polling the cache during MDS shutdown.
410	:Type: 32-bit Integer
411	:Default: ``0``
412
413
414	``mds thrash exports``
415
416	:Description: Ceph will randomly export subtrees between nodes (testing only).
417	:Type: 32-bit Integer
418	:Default: ``0``
419
420
421	``mds thrash fragments``
422
423	:Description: Ceph will randomly fragment or merge directories.
424	:Type: 32-bit Integer
425	:Default: ``0``
426
427
428	``mds dump cache on map``
429
430	:Description: Ceph will dump the MDS cache contents to a file on each MDSMap.
431	:Type: Boolean
432	:Default: ``false``
433
434
435	``mds dump cache after rejoin``
436
437	:Description: Ceph will dump MDS cache contents to a file after
438	rejoining the cache (during recovery).
439
440	:Type: Boolean
441	:Default: ``false``
442
443
444	``mds verify scatter``
445
446	:Description: Ceph will assert that various scatter/gather invariants
447	are ``true`` (developers only).
448
449	:Type: Boolean
450	:Default: ``false``
451
452
453	``mds debug scatterstat``
454
455	:Description: Ceph will assert that various recursive stat invariants
456	are ``true`` (for developers only).
457
458	:Type: Boolean
459	:Default: ``false``
460
461
462	``mds debug frag``
463
464	:Description: Ceph will verify directory fragmentation invariants
465	when convenient (developers only).
466
467	:Type: Boolean
468	:Default: ``false``
469
470
471	``mds debug auth pins``
472
473	:Description: The debug auth pin invariants (for developers only).
474	:Type: Boolean
475	:Default: ``false``
476
477
478	``mds debug subtrees``
479
480	:Description: The debug subtree invariants (for developers only).
481	:Type: Boolean
482	:Default: ``false``
483
484
485	``mds kill mdstable at``
486
487	:Description: Ceph will inject MDS failure in MDSTable code
488	(for developers only).
489
490	:Type: 32-bit Integer
491	:Default: ``0``
492
493
494	``mds kill export at``
495
496	:Description: Ceph will inject MDS failure in the subtree export code
497	(for developers only).
498
499	:Type: 32-bit Integer
500	:Default: ``0``
501
502
503	``mds kill import at``
504
505	:Description: Ceph will inject MDS failure in the subtree import code
506	(for developers only).
507
508	:Type: 32-bit Integer
509	:Default: ``0``
510
511
512	``mds kill link at``
513
514	:Description: Ceph will inject MDS failure in hard link code
515	(for developers only).
516
517	:Type: 32-bit Integer
518	:Default: ``0``
519
520
521	``mds kill rename at``
522
523	:Description: Ceph will inject MDS failure in the rename code
524	(for developers only).
525
526	:Type: 32-bit Integer
527	:Default: ``0``
528
529
530	``mds wipe sessions``
531
532	:Description: Ceph will delete all client sessions on startup
533	(for testing only).
534
535	:Type: Boolean
11fdf7f2	536	:Default: ``false``
7c673cae FG	537
	538
	539	``mds wipe ino prealloc``
	540
	541	:Description: Ceph will delete ino preallocation metadata on startup
	542	(for testing only).
	543
	544	:Type: Boolean
11fdf7f2	545	:Default: ``false``
7c673cae FG	546
	547
	548	``mds skip ino``
	549
	550	:Description: The number of inode numbers to skip on startup
	551	(for testing only).
	552
	553	:Type: 32-bit Integer
	554	:Default: ``0``
	555
	556
	557	``mds standby for name``
	558
	559	:Description: An MDS daemon will standby for another MDS daemon of the name
	560	specified in this setting.
	561
	562	:Type: String
	563	:Default: N/A
	564
	565
	566	``mds standby for rank``
	567
	568	:Description: An MDS daemon will standby for an MDS daemon of this rank.
	569	:Type: 32-bit Integer
	570	:Default: ``-1``
	571
	572
	573	``mds standby replay``
	574
	575	:Description: Determines whether a ``ceph-mds`` daemon should poll and replay
	576	the log of an active MDS (hot standby).
	577
	578	:Type: Boolean
	579	:Default: ``false``
3efd9988 FG	580
	581
	582	``mds min caps per client``
	583
	584	:Description: Set the minimum number of capabilities a client may hold.
	585	:Type: Integer
	586	:Default: ``100``
	587
	588
	589	``mds max ratio caps per client``
	590
	591	:Description: Set the maximum ratio of current caps that may be recalled during MDS cache pressure.
	592	:Type: Float
	593	:Default: ``0.8``