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1
2The SGI XFS Filesystem
3======================
4
5XFS is a high performance journaling filesystem which originated
6on the SGI IRIX platform. It is completely multi-threaded, can
7support large files and large filesystems, extended attributes,
8variable block sizes, is extent based, and makes extensive use of
9Btrees (directories, extents, free space) to aid both performance
10and scalability.
11
12Refer to the documentation at https://xfs.wiki.kernel.org/
13for further details. This implementation is on-disk compatible
14with the IRIX version of XFS.
15
16
17Mount Options
18=============
19
20When mounting an XFS filesystem, the following options are accepted.
21For boolean mount options, the names with the (*) suffix is the
22default behaviour.
23
24 allocsize=size
25 Sets the buffered I/O end-of-file preallocation size when
26 doing delayed allocation writeout (default size is 64KiB).
27 Valid values for this option are page size (typically 4KiB)
28 through to 1GiB, inclusive, in power-of-2 increments.
29
30 The default behaviour is for dynamic end-of-file
31 preallocation size, which uses a set of heuristics to
32 optimise the preallocation size based on the current
33 allocation patterns within the file and the access patterns
34 to the file. Specifying a fixed allocsize value turns off
35 the dynamic behaviour.
36
37 attr2
38 noattr2
39 The options enable/disable an "opportunistic" improvement to
40 be made in the way inline extended attributes are stored
41 on-disk. When the new form is used for the first time when
42 attr2 is selected (either when setting or removing extended
43 attributes) the on-disk superblock feature bit field will be
44 updated to reflect this format being in use.
45
46 The default behaviour is determined by the on-disk feature
47 bit indicating that attr2 behaviour is active. If either
48 mount option it set, then that becomes the new default used
49 by the filesystem.
50
51 CRC enabled filesystems always use the attr2 format, and so
52 will reject the noattr2 mount option if it is set.
53
54 discard
55 nodiscard (*)
56 Enable/disable the issuing of commands to let the block
57 device reclaim space freed by the filesystem. This is
58 useful for SSD devices, thinly provisioned LUNs and virtual
59 machine images, but may have a performance impact.
60
61 Note: It is currently recommended that you use the fstrim
62 application to discard unused blocks rather than the discard
63 mount option because the performance impact of this option
64 is quite severe.
65
66 grpid/bsdgroups
67 nogrpid/sysvgroups (*)
68 These options define what group ID a newly created file
69 gets. When grpid is set, it takes the group ID of the
70 directory in which it is created; otherwise it takes the
71 fsgid of the current process, unless the directory has the
72 setgid bit set, in which case it takes the gid from the
73 parent directory, and also gets the setgid bit set if it is
74 a directory itself.
75
76 filestreams
77 Make the data allocator use the filestreams allocation mode
78 across the entire filesystem rather than just on directories
79 configured to use it.
80
81 ikeep
82 noikeep (*)
83 When ikeep is specified, XFS does not delete empty inode
84 clusters and keeps them around on disk. When noikeep is
85 specified, empty inode clusters are returned to the free
86 space pool.
87
88 inode32
89 inode64 (*)
90 When inode32 is specified, it indicates that XFS limits
91 inode creation to locations which will not result in inode
92 numbers with more than 32 bits of significance.
93
94 When inode64 is specified, it indicates that XFS is allowed
95 to create inodes at any location in the filesystem,
96 including those which will result in inode numbers occupying
97 more than 32 bits of significance.
98
99 inode32 is provided for backwards compatibility with older
100 systems and applications, since 64 bits inode numbers might
101 cause problems for some applications that cannot handle
102 large inode numbers. If applications are in use which do
103 not handle inode numbers bigger than 32 bits, the inode32
104 option should be specified.
105
106
107 largeio
108 nolargeio (*)
109 If "nolargeio" is specified, the optimal I/O reported in
110 st_blksize by stat(2) will be as small as possible to allow
111 user applications to avoid inefficient read/modify/write
112 I/O. This is typically the page size of the machine, as
113 this is the granularity of the page cache.
114
115 If "largeio" specified, a filesystem that was created with a
116 "swidth" specified will return the "swidth" value (in bytes)
117 in st_blksize. If the filesystem does not have a "swidth"
118 specified but does specify an "allocsize" then "allocsize"
119 (in bytes) will be returned instead. Otherwise the behaviour
120 is the same as if "nolargeio" was specified.
121
122 logbufs=value
123 Set the number of in-memory log buffers. Valid numbers
124 range from 2-8 inclusive.
125
126 The default value is 8 buffers.
127
128 If the memory cost of 8 log buffers is too high on small
129 systems, then it may be reduced at some cost to performance
130 on metadata intensive workloads. The logbsize option below
131 controls the size of each buffer and so is also relevant to
132 this case.
133
134 logbsize=value
135 Set the size of each in-memory log buffer. The size may be
136 specified in bytes, or in kilobytes with a "k" suffix.
137 Valid sizes for version 1 and version 2 logs are 16384 (16k)
138 and 32768 (32k). Valid sizes for version 2 logs also
139 include 65536 (64k), 131072 (128k) and 262144 (256k). The
140 logbsize must be an integer multiple of the log
141 stripe unit configured at mkfs time.
142
143 The default value for for version 1 logs is 32768, while the
144 default value for version 2 logs is MAX(32768, log_sunit).
145
146 logdev=device and rtdev=device
147 Use an external log (metadata journal) and/or real-time device.
148 An XFS filesystem has up to three parts: a data section, a log
149 section, and a real-time section. The real-time section is
150 optional, and the log section can be separate from the data
151 section or contained within it.
152
153 noalign
154 Data allocations will not be aligned at stripe unit
155 boundaries. This is only relevant to filesystems created
156 with non-zero data alignment parameters (sunit, swidth) by
157 mkfs.
158
159 norecovery
160 The filesystem will be mounted without running log recovery.
161 If the filesystem was not cleanly unmounted, it is likely to
162 be inconsistent when mounted in "norecovery" mode.
163 Some files or directories may not be accessible because of this.
164 Filesystems mounted "norecovery" must be mounted read-only or
165 the mount will fail.
166
167 nouuid
168 Don't check for double mounted file systems using the file
169 system uuid. This is useful to mount LVM snapshot volumes,
170 and often used in combination with "norecovery" for mounting
171 read-only snapshots.
172
173 noquota
174 Forcibly turns off all quota accounting and enforcement
175 within the filesystem.
176
177 uquota/usrquota/uqnoenforce/quota
178 User disk quota accounting enabled, and limits (optionally)
179 enforced. Refer to xfs_quota(8) for further details.
180
181 gquota/grpquota/gqnoenforce
182 Group disk quota accounting enabled and limits (optionally)
183 enforced. Refer to xfs_quota(8) for further details.
184
185 pquota/prjquota/pqnoenforce
186 Project disk quota accounting enabled and limits (optionally)
187 enforced. Refer to xfs_quota(8) for further details.
188
189 sunit=value and swidth=value
190 Used to specify the stripe unit and width for a RAID device
191 or a stripe volume. "value" must be specified in 512-byte
192 block units. These options are only relevant to filesystems
193 that were created with non-zero data alignment parameters.
194
195 The sunit and swidth parameters specified must be compatible
196 with the existing filesystem alignment characteristics. In
197 general, that means the only valid changes to sunit are
198 increasing it by a power-of-2 multiple. Valid swidth values
199 are any integer multiple of a valid sunit value.
200
201 Typically the only time these mount options are necessary if
202 after an underlying RAID device has had it's geometry
203 modified, such as adding a new disk to a RAID5 lun and
204 reshaping it.
205
206 swalloc
207 Data allocations will be rounded up to stripe width boundaries
208 when the current end of file is being extended and the file
209 size is larger than the stripe width size.
210
211 wsync
212 When specified, all filesystem namespace operations are
213 executed synchronously. This ensures that when the namespace
214 operation (create, unlink, etc) completes, the change to the
215 namespace is on stable storage. This is useful in HA setups
216 where failover must not result in clients seeing
217 inconsistent namespace presentation during or after a
218 failover event.
219
220
221Deprecated Mount Options
222========================
223
224 Name Removal Schedule
225 ---- ----------------
226 barrier no earlier than v4.15
227 nobarrier no earlier than v4.15
228
229
230Removed Mount Options
231=====================
232
233 Name Removed
234 ---- -------
235 delaylog/nodelaylog v4.0
236 ihashsize v4.0
237 irixsgid v4.0
238 osyncisdsync/osyncisosync v4.0
239
240
241sysctls
242=======
243
244The following sysctls are available for the XFS filesystem:
245
246 fs.xfs.stats_clear (Min: 0 Default: 0 Max: 1)
247 Setting this to "1" clears accumulated XFS statistics
248 in /proc/fs/xfs/stat. It then immediately resets to "0".
249
250 fs.xfs.xfssyncd_centisecs (Min: 100 Default: 3000 Max: 720000)
251 The interval at which the filesystem flushes metadata
252 out to disk and runs internal cache cleanup routines.
253
254 fs.xfs.filestream_centisecs (Min: 1 Default: 3000 Max: 360000)
255 The interval at which the filesystem ages filestreams cache
256 references and returns timed-out AGs back to the free stream
257 pool.
258
259 fs.xfs.speculative_prealloc_lifetime
260 (Units: seconds Min: 1 Default: 300 Max: 86400)
261 The interval at which the background scanning for inodes
262 with unused speculative preallocation runs. The scan
263 removes unused preallocation from clean inodes and releases
264 the unused space back to the free pool.
265
266 fs.xfs.error_level (Min: 0 Default: 3 Max: 11)
267 A volume knob for error reporting when internal errors occur.
268 This will generate detailed messages & backtraces for filesystem
269 shutdowns, for example. Current threshold values are:
270
271 XFS_ERRLEVEL_OFF: 0
272 XFS_ERRLEVEL_LOW: 1
273 XFS_ERRLEVEL_HIGH: 5
274
275 fs.xfs.panic_mask (Min: 0 Default: 0 Max: 255)
276 Causes certain error conditions to call BUG(). Value is a bitmask;
277 OR together the tags which represent errors which should cause panics:
278
279 XFS_NO_PTAG 0
280 XFS_PTAG_IFLUSH 0x00000001
281 XFS_PTAG_LOGRES 0x00000002
282 XFS_PTAG_AILDELETE 0x00000004
283 XFS_PTAG_ERROR_REPORT 0x00000008
284 XFS_PTAG_SHUTDOWN_CORRUPT 0x00000010
285 XFS_PTAG_SHUTDOWN_IOERROR 0x00000020
286 XFS_PTAG_SHUTDOWN_LOGERROR 0x00000040
287 XFS_PTAG_FSBLOCK_ZERO 0x00000080
288
289 This option is intended for debugging only.
290
291 fs.xfs.irix_symlink_mode (Min: 0 Default: 0 Max: 1)
292 Controls whether symlinks are created with mode 0777 (default)
293 or whether their mode is affected by the umask (irix mode).
294
295 fs.xfs.irix_sgid_inherit (Min: 0 Default: 0 Max: 1)
296 Controls files created in SGID directories.
297 If the group ID of the new file does not match the effective group
298 ID or one of the supplementary group IDs of the parent dir, the
299 ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl
300 is set.
301
302 fs.xfs.inherit_sync (Min: 0 Default: 1 Max: 1)
303 Setting this to "1" will cause the "sync" flag set
304 by the xfs_io(8) chattr command on a directory to be
305 inherited by files in that directory.
306
307 fs.xfs.inherit_nodump (Min: 0 Default: 1 Max: 1)
308 Setting this to "1" will cause the "nodump" flag set
309 by the xfs_io(8) chattr command on a directory to be
310 inherited by files in that directory.
311
312 fs.xfs.inherit_noatime (Min: 0 Default: 1 Max: 1)
313 Setting this to "1" will cause the "noatime" flag set
314 by the xfs_io(8) chattr command on a directory to be
315 inherited by files in that directory.
316
317 fs.xfs.inherit_nosymlinks (Min: 0 Default: 1 Max: 1)
318 Setting this to "1" will cause the "nosymlinks" flag set
319 by the xfs_io(8) chattr command on a directory to be
320 inherited by files in that directory.
321
322 fs.xfs.inherit_nodefrag (Min: 0 Default: 1 Max: 1)
323 Setting this to "1" will cause the "nodefrag" flag set
324 by the xfs_io(8) chattr command on a directory to be
325 inherited by files in that directory.
326
327 fs.xfs.rotorstep (Min: 1 Default: 1 Max: 256)
328 In "inode32" allocation mode, this option determines how many
329 files the allocator attempts to allocate in the same allocation
330 group before moving to the next allocation group. The intent
331 is to control the rate at which the allocator moves between
332 allocation groups when allocating extents for new files.
333
334Deprecated Sysctls
335==================
336
337None at present.
338
339
340Removed Sysctls
341===============
342
343 Name Removed
344 ---- -------
345 fs.xfs.xfsbufd_centisec v4.0
346 fs.xfs.age_buffer_centisecs v4.0
347
348
349Error handling
350==============
351
352XFS can act differently according to the type of error found during its
353operation. The implementation introduces the following concepts to the error
354handler:
355
356 -failure speed:
357 Defines how fast XFS should propagate an error upwards when a specific
358 error is found during the filesystem operation. It can propagate
359 immediately, after a defined number of retries, after a set time period,
360 or simply retry forever.
361
362 -error classes:
363 Specifies the subsystem the error configuration will apply to, such as
364 metadata IO or memory allocation. Different subsystems will have
365 different error handlers for which behaviour can be configured.
366
367 -error handlers:
368 Defines the behavior for a specific error.
369
370The filesystem behavior during an error can be set via sysfs files. Each
371error handler works independently - the first condition met by an error handler
372for a specific class will cause the error to be propagated rather than reset and
373retried.
374
375The action taken by the filesystem when the error is propagated is context
376dependent - it may cause a shut down in the case of an unrecoverable error,
377it may be reported back to userspace, or it may even be ignored because
378there's nothing useful we can with the error or anyone we can report it to (e.g.
379during unmount).
380
381The configuration files are organized into the following hierarchy for each
382mounted filesystem:
383
384 /sys/fs/xfs/<dev>/error/<class>/<error>/
385
386Where:
387 <dev>
388 The short device name of the mounted filesystem. This is the same device
389 name that shows up in XFS kernel error messages as "XFS(<dev>): ..."
390
391 <class>
392 The subsystem the error configuration belongs to. As of 4.9, the defined
393 classes are:
394
395 - "metadata": applies metadata buffer write IO
396
397 <error>
398 The individual error handler configurations.
399
400
401Each filesystem has "global" error configuration options defined in their top
402level directory:
403
404 /sys/fs/xfs/<dev>/error/
405
406 fail_at_unmount (Min: 0 Default: 1 Max: 1)
407 Defines the filesystem error behavior at unmount time.
408
409 If set to a value of 1, XFS will override all other error configurations
410 during unmount and replace them with "immediate fail" characteristics.
411 i.e. no retries, no retry timeout. This will always allow unmount to
412 succeed when there are persistent errors present.
413
414 If set to 0, the configured retry behaviour will continue until all
415 retries and/or timeouts have been exhausted. This will delay unmount
416 completion when there are persistent errors, and it may prevent the
417 filesystem from ever unmounting fully in the case of "retry forever"
418 handler configurations.
419
420 Note: there is no guarantee that fail_at_unmount can be set whilst an
421 unmount is in progress. It is possible that the sysfs entries are
422 removed by the unmounting filesystem before a "retry forever" error
423 handler configuration causes unmount to hang, and hence the filesystem
424 must be configured appropriately before unmount begins to prevent
425 unmount hangs.
426
427Each filesystem has specific error class handlers that define the error
428propagation behaviour for specific errors. There is also a "default" error
429handler defined, which defines the behaviour for all errors that don't have
430specific handlers defined. Where multiple retry constraints are configuredi for
431a single error, the first retry configuration that expires will cause the error
432to be propagated. The handler configurations are found in the directory:
433
434 /sys/fs/xfs/<dev>/error/<class>/<error>/
435
436 max_retries (Min: -1 Default: Varies Max: INTMAX)
437 Defines the allowed number of retries of a specific error before
438 the filesystem will propagate the error. The retry count for a given
439 error context (e.g. a specific metadata buffer) is reset every time
440 there is a successful completion of the operation.
441
442 Setting the value to "-1" will cause XFS to retry forever for this
443 specific error.
444
445 Setting the value to "0" will cause XFS to fail immediately when the
446 specific error is reported.
447
448 Setting the value to "N" (where 0 < N < Max) will make XFS retry the
449 operation "N" times before propagating the error.
450
451 retry_timeout_seconds (Min: -1 Default: Varies Max: 1 day)
452 Define the amount of time (in seconds) that the filesystem is
453 allowed to retry its operations when the specific error is
454 found.
455
456 Setting the value to "-1" will allow XFS to retry forever for this
457 specific error.
458
459 Setting the value to "0" will cause XFS to fail immediately when the
460 specific error is reported.
461
462 Setting the value to "N" (where 0 < N < Max) will allow XFS to retry the
463 operation for up to "N" seconds before propagating the error.
464
465Note: The default behaviour for a specific error handler is dependent on both
466the class and error context. For example, the default values for
467"metadata/ENODEV" are "0" rather than "-1" so that this error handler defaults
468to "fail immediately" behaviour. This is done because ENODEV is a fatal,
469unrecoverable error no matter how many times the metadata IO is retried.
1
2The SGI XFS Filesystem
3======================
4
5XFS is a high performance journaling filesystem which originated
6on the SGI IRIX platform. It is completely multi-threaded, can
7support large files and large filesystems, extended attributes,
8variable block sizes, is extent based, and makes extensive use of
9Btrees (directories, extents, free space) to aid both performance
10and scalability.
11
12Refer to the documentation at http://oss.sgi.com/projects/xfs/
13for further details. This implementation is on-disk compatible
14with the IRIX version of XFS.
15
16
17Mount Options
18=============
19
20When mounting an XFS filesystem, the following options are accepted.
21For boolean mount options, the names with the (*) suffix is the
22default behaviour.
23
24 allocsize=size
25 Sets the buffered I/O end-of-file preallocation size when
26 doing delayed allocation writeout (default size is 64KiB).
27 Valid values for this option are page size (typically 4KiB)
28 through to 1GiB, inclusive, in power-of-2 increments.
29
30 The default behaviour is for dynamic end-of-file
31 preallocation size, which uses a set of heuristics to
32 optimise the preallocation size based on the current
33 allocation patterns within the file and the access patterns
34 to the file. Specifying a fixed allocsize value turns off
35 the dynamic behaviour.
36
37 attr2
38 noattr2
39 The options enable/disable an "opportunistic" improvement to
40 be made in the way inline extended attributes are stored
41 on-disk. When the new form is used for the first time when
42 attr2 is selected (either when setting or removing extended
43 attributes) the on-disk superblock feature bit field will be
44 updated to reflect this format being in use.
45
46 The default behaviour is determined by the on-disk feature
47 bit indicating that attr2 behaviour is active. If either
48 mount option it set, then that becomes the new default used
49 by the filesystem.
50
51 CRC enabled filesystems always use the attr2 format, and so
52 will reject the noattr2 mount option if it is set.
53
54 barrier (*)
55 nobarrier
56 Enables/disables the use of block layer write barriers for
57 writes into the journal and for data integrity operations.
58 This allows for drive level write caching to be enabled, for
59 devices that support write barriers.
60
61 discard
62 nodiscard (*)
63 Enable/disable the issuing of commands to let the block
64 device reclaim space freed by the filesystem. This is
65 useful for SSD devices, thinly provisioned LUNs and virtual
66 machine images, but may have a performance impact.
67
68 Note: It is currently recommended that you use the fstrim
69 application to discard unused blocks rather than the discard
70 mount option because the performance impact of this option
71 is quite severe.
72
73 grpid/bsdgroups
74 nogrpid/sysvgroups (*)
75 These options define what group ID a newly created file
76 gets. When grpid is set, it takes the group ID of the
77 directory in which it is created; otherwise it takes the
78 fsgid of the current process, unless the directory has the
79 setgid bit set, in which case it takes the gid from the
80 parent directory, and also gets the setgid bit set if it is
81 a directory itself.
82
83 filestreams
84 Make the data allocator use the filestreams allocation mode
85 across the entire filesystem rather than just on directories
86 configured to use it.
87
88 ikeep
89 noikeep (*)
90 When ikeep is specified, XFS does not delete empty inode
91 clusters and keeps them around on disk. When noikeep is
92 specified, empty inode clusters are returned to the free
93 space pool.
94
95 inode32
96 inode64 (*)
97 When inode32 is specified, it indicates that XFS limits
98 inode creation to locations which will not result in inode
99 numbers with more than 32 bits of significance.
100
101 When inode64 is specified, it indicates that XFS is allowed
102 to create inodes at any location in the filesystem,
103 including those which will result in inode numbers occupying
104 more than 32 bits of significance.
105
106 inode32 is provided for backwards compatibility with older
107 systems and applications, since 64 bits inode numbers might
108 cause problems for some applications that cannot handle
109 large inode numbers. If applications are in use which do
110 not handle inode numbers bigger than 32 bits, the inode32
111 option should be specified.
112
113
114 largeio
115 nolargeio (*)
116 If "nolargeio" is specified, the optimal I/O reported in
117 st_blksize by stat(2) will be as small as possible to allow
118 user applications to avoid inefficient read/modify/write
119 I/O. This is typically the page size of the machine, as
120 this is the granularity of the page cache.
121
122 If "largeio" specified, a filesystem that was created with a
123 "swidth" specified will return the "swidth" value (in bytes)
124 in st_blksize. If the filesystem does not have a "swidth"
125 specified but does specify an "allocsize" then "allocsize"
126 (in bytes) will be returned instead. Otherwise the behaviour
127 is the same as if "nolargeio" was specified.
128
129 logbufs=value
130 Set the number of in-memory log buffers. Valid numbers
131 range from 2-8 inclusive.
132
133 The default value is 8 buffers.
134
135 If the memory cost of 8 log buffers is too high on small
136 systems, then it may be reduced at some cost to performance
137 on metadata intensive workloads. The logbsize option below
138 controls the size of each buffer and so is also relevant to
139 this case.
140
141 logbsize=value
142 Set the size of each in-memory log buffer. The size may be
143 specified in bytes, or in kilobytes with a "k" suffix.
144 Valid sizes for version 1 and version 2 logs are 16384 (16k)
145 and 32768 (32k). Valid sizes for version 2 logs also
146 include 65536 (64k), 131072 (128k) and 262144 (256k). The
147 logbsize must be an integer multiple of the log
148 stripe unit configured at mkfs time.
149
150 The default value for for version 1 logs is 32768, while the
151 default value for version 2 logs is MAX(32768, log_sunit).
152
153 logdev=device and rtdev=device
154 Use an external log (metadata journal) and/or real-time device.
155 An XFS filesystem has up to three parts: a data section, a log
156 section, and a real-time section. The real-time section is
157 optional, and the log section can be separate from the data
158 section or contained within it.
159
160 noalign
161 Data allocations will not be aligned at stripe unit
162 boundaries. This is only relevant to filesystems created
163 with non-zero data alignment parameters (sunit, swidth) by
164 mkfs.
165
166 norecovery
167 The filesystem will be mounted without running log recovery.
168 If the filesystem was not cleanly unmounted, it is likely to
169 be inconsistent when mounted in "norecovery" mode.
170 Some files or directories may not be accessible because of this.
171 Filesystems mounted "norecovery" must be mounted read-only or
172 the mount will fail.
173
174 nouuid
175 Don't check for double mounted file systems using the file
176 system uuid. This is useful to mount LVM snapshot volumes,
177 and often used in combination with "norecovery" for mounting
178 read-only snapshots.
179
180 noquota
181 Forcibly turns off all quota accounting and enforcement
182 within the filesystem.
183
184 uquota/usrquota/uqnoenforce/quota
185 User disk quota accounting enabled, and limits (optionally)
186 enforced. Refer to xfs_quota(8) for further details.
187
188 gquota/grpquota/gqnoenforce
189 Group disk quota accounting enabled and limits (optionally)
190 enforced. Refer to xfs_quota(8) for further details.
191
192 pquota/prjquota/pqnoenforce
193 Project disk quota accounting enabled and limits (optionally)
194 enforced. Refer to xfs_quota(8) for further details.
195
196 sunit=value and swidth=value
197 Used to specify the stripe unit and width for a RAID device
198 or a stripe volume. "value" must be specified in 512-byte
199 block units. These options are only relevant to filesystems
200 that were created with non-zero data alignment parameters.
201
202 The sunit and swidth parameters specified must be compatible
203 with the existing filesystem alignment characteristics. In
204 general, that means the only valid changes to sunit are
205 increasing it by a power-of-2 multiple. Valid swidth values
206 are any integer multiple of a valid sunit value.
207
208 Typically the only time these mount options are necessary if
209 after an underlying RAID device has had it's geometry
210 modified, such as adding a new disk to a RAID5 lun and
211 reshaping it.
212
213 swalloc
214 Data allocations will be rounded up to stripe width boundaries
215 when the current end of file is being extended and the file
216 size is larger than the stripe width size.
217
218 wsync
219 When specified, all filesystem namespace operations are
220 executed synchronously. This ensures that when the namespace
221 operation (create, unlink, etc) completes, the change to the
222 namespace is on stable storage. This is useful in HA setups
223 where failover must not result in clients seeing
224 inconsistent namespace presentation during or after a
225 failover event.
226
227
228Deprecated Mount Options
229========================
230
231None at present.
232
233
234Removed Mount Options
235=====================
236
237 Name Removed
238 ---- -------
239 delaylog/nodelaylog v4.0
240 ihashsize v4.0
241 irixsgid v4.0
242 osyncisdsync/osyncisosync v4.0
243
244
245sysctls
246=======
247
248The following sysctls are available for the XFS filesystem:
249
250 fs.xfs.stats_clear (Min: 0 Default: 0 Max: 1)
251 Setting this to "1" clears accumulated XFS statistics
252 in /proc/fs/xfs/stat. It then immediately resets to "0".
253
254 fs.xfs.xfssyncd_centisecs (Min: 100 Default: 3000 Max: 720000)
255 The interval at which the filesystem flushes metadata
256 out to disk and runs internal cache cleanup routines.
257
258 fs.xfs.filestream_centisecs (Min: 1 Default: 3000 Max: 360000)
259 The interval at which the filesystem ages filestreams cache
260 references and returns timed-out AGs back to the free stream
261 pool.
262
263 fs.xfs.speculative_prealloc_lifetime
264 (Units: seconds Min: 1 Default: 300 Max: 86400)
265 The interval at which the background scanning for inodes
266 with unused speculative preallocation runs. The scan
267 removes unused preallocation from clean inodes and releases
268 the unused space back to the free pool.
269
270 fs.xfs.error_level (Min: 0 Default: 3 Max: 11)
271 A volume knob for error reporting when internal errors occur.
272 This will generate detailed messages & backtraces for filesystem
273 shutdowns, for example. Current threshold values are:
274
275 XFS_ERRLEVEL_OFF: 0
276 XFS_ERRLEVEL_LOW: 1
277 XFS_ERRLEVEL_HIGH: 5
278
279 fs.xfs.panic_mask (Min: 0 Default: 0 Max: 255)
280 Causes certain error conditions to call BUG(). Value is a bitmask;
281 OR together the tags which represent errors which should cause panics:
282
283 XFS_NO_PTAG 0
284 XFS_PTAG_IFLUSH 0x00000001
285 XFS_PTAG_LOGRES 0x00000002
286 XFS_PTAG_AILDELETE 0x00000004
287 XFS_PTAG_ERROR_REPORT 0x00000008
288 XFS_PTAG_SHUTDOWN_CORRUPT 0x00000010
289 XFS_PTAG_SHUTDOWN_IOERROR 0x00000020
290 XFS_PTAG_SHUTDOWN_LOGERROR 0x00000040
291 XFS_PTAG_FSBLOCK_ZERO 0x00000080
292
293 This option is intended for debugging only.
294
295 fs.xfs.irix_symlink_mode (Min: 0 Default: 0 Max: 1)
296 Controls whether symlinks are created with mode 0777 (default)
297 or whether their mode is affected by the umask (irix mode).
298
299 fs.xfs.irix_sgid_inherit (Min: 0 Default: 0 Max: 1)
300 Controls files created in SGID directories.
301 If the group ID of the new file does not match the effective group
302 ID or one of the supplementary group IDs of the parent dir, the
303 ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl
304 is set.
305
306 fs.xfs.inherit_sync (Min: 0 Default: 1 Max: 1)
307 Setting this to "1" will cause the "sync" flag set
308 by the xfs_io(8) chattr command on a directory to be
309 inherited by files in that directory.
310
311 fs.xfs.inherit_nodump (Min: 0 Default: 1 Max: 1)
312 Setting this to "1" will cause the "nodump" flag set
313 by the xfs_io(8) chattr command on a directory to be
314 inherited by files in that directory.
315
316 fs.xfs.inherit_noatime (Min: 0 Default: 1 Max: 1)
317 Setting this to "1" will cause the "noatime" flag set
318 by the xfs_io(8) chattr command on a directory to be
319 inherited by files in that directory.
320
321 fs.xfs.inherit_nosymlinks (Min: 0 Default: 1 Max: 1)
322 Setting this to "1" will cause the "nosymlinks" flag set
323 by the xfs_io(8) chattr command on a directory to be
324 inherited by files in that directory.
325
326 fs.xfs.inherit_nodefrag (Min: 0 Default: 1 Max: 1)
327 Setting this to "1" will cause the "nodefrag" flag set
328 by the xfs_io(8) chattr command on a directory to be
329 inherited by files in that directory.
330
331 fs.xfs.rotorstep (Min: 1 Default: 1 Max: 256)
332 In "inode32" allocation mode, this option determines how many
333 files the allocator attempts to allocate in the same allocation
334 group before moving to the next allocation group. The intent
335 is to control the rate at which the allocator moves between
336 allocation groups when allocating extents for new files.
337
338Deprecated Sysctls
339==================
340
341None at present.
342
343
344Removed Sysctls
345===============
346
347 Name Removed
348 ---- -------
349 fs.xfs.xfsbufd_centisec v4.0
350 fs.xfs.age_buffer_centisecs v4.0