+.. SPDX-License-Identifier: GPL-2.0
+======================
The SGI XFS Filesystem
======================
=============
When mounting an XFS filesystem, the following options are accepted.
-For boolean mount options, the names with the (*) suffix is the
-default behaviour.
allocsize=size
Sets the buffered I/O end-of-file preallocation size when
preallocation size, which uses a set of heuristics to
optimise the preallocation size based on the current
allocation patterns within the file and the access patterns
- to the file. Specifying a fixed allocsize value turns off
+ to the file. Specifying a fixed ``allocsize`` value turns off
the dynamic behaviour.
- attr2
- noattr2
+ attr2 or noattr2
The options enable/disable an "opportunistic" improvement to
be made in the way inline extended attributes are stored
on-disk. When the new form is used for the first time when
- attr2 is selected (either when setting or removing extended
+ ``attr2`` is selected (either when setting or removing extended
attributes) the on-disk superblock feature bit field will be
updated to reflect this format being in use.
The default behaviour is determined by the on-disk feature
- bit indicating that attr2 behaviour is active. If either
- mount option it set, then that becomes the new default used
+ bit indicating that ``attr2`` behaviour is active. If either
+ mount option is set, then that becomes the new default used
by the filesystem.
- CRC enabled filesystems always use the attr2 format, and so
- will reject the noattr2 mount option if it is set.
+ CRC enabled filesystems always use the ``attr2`` format, and so
+ will reject the ``noattr2`` mount option if it is set.
- discard
- nodiscard (*)
+ discard or nodiscard (default)
Enable/disable the issuing of commands to let the block
device reclaim space freed by the filesystem. This is
useful for SSD devices, thinly provisioned LUNs and virtual
machine images, but may have a performance impact.
- Note: It is currently recommended that you use the fstrim
- application to discard unused blocks rather than the discard
+ Note: It is currently recommended that you use the ``fstrim``
+ application to ``discard`` unused blocks rather than the ``discard``
mount option because the performance impact of this option
is quite severe.
- grpid/bsdgroups
- nogrpid/sysvgroups (*)
+ grpid/bsdgroups or nogrpid/sysvgroups (default)
These options define what group ID a newly created file
- gets. When grpid is set, it takes the group ID of the
+ gets. When ``grpid`` is set, it takes the group ID of the
directory in which it is created; otherwise it takes the
- fsgid of the current process, unless the directory has the
- setgid bit set, in which case it takes the gid from the
- parent directory, and also gets the setgid bit set if it is
+ ``fsgid`` of the current process, unless the directory has the
+ ``setgid`` bit set, in which case it takes the ``gid`` from the
+ parent directory, and also gets the ``setgid`` bit set if it is
a directory itself.
filestreams
across the entire filesystem rather than just on directories
configured to use it.
- ikeep
- noikeep (*)
- When ikeep is specified, XFS does not delete empty inode
- clusters and keeps them around on disk. When noikeep is
+ ikeep or noikeep (default)
+ When ``ikeep`` is specified, XFS does not delete empty inode
+ clusters and keeps them around on disk. When ``noikeep`` is
specified, empty inode clusters are returned to the free
space pool.
- inode32
- inode64 (*)
- When inode32 is specified, it indicates that XFS limits
+ inode32 or inode64 (default)
+ When ``inode32`` is specified, it indicates that XFS limits
inode creation to locations which will not result in inode
numbers with more than 32 bits of significance.
- When inode64 is specified, it indicates that XFS is allowed
+ When ``inode64`` is specified, it indicates that XFS is allowed
to create inodes at any location in the filesystem,
including those which will result in inode numbers occupying
- more than 32 bits of significance.
+ more than 32 bits of significance.
- inode32 is provided for backwards compatibility with older
+ ``inode32`` is provided for backwards compatibility with older
systems and applications, since 64 bits inode numbers might
cause problems for some applications that cannot handle
large inode numbers. If applications are in use which do
- not handle inode numbers bigger than 32 bits, the inode32
+ not handle inode numbers bigger than 32 bits, the ``inode32``
option should be specified.
-
- largeio
- nolargeio (*)
- If "nolargeio" is specified, the optimal I/O reported in
- st_blksize by stat(2) will be as small as possible to allow
+ largeio or nolargeio (default)
+ If ``nolargeio`` is specified, the optimal I/O reported in
+ ``st_blksize`` by **stat(2)** will be as small as possible to allow
user applications to avoid inefficient read/modify/write
I/O. This is typically the page size of the machine, as
this is the granularity of the page cache.
- If "largeio" specified, a filesystem that was created with a
- "swidth" specified will return the "swidth" value (in bytes)
- in st_blksize. If the filesystem does not have a "swidth"
- specified but does specify an "allocsize" then "allocsize"
+ If ``largeio`` is specified, a filesystem that was created with a
+ ``swidth`` specified will return the ``swidth`` value (in bytes)
+ in ``st_blksize``. If the filesystem does not have a ``swidth``
+ specified but does specify an ``allocsize`` then ``allocsize``
(in bytes) will be returned instead. Otherwise the behaviour
- is the same as if "nolargeio" was specified.
+ is the same as if ``nolargeio`` was specified.
logbufs=value
Set the number of in-memory log buffers. Valid numbers
If the memory cost of 8 log buffers is too high on small
systems, then it may be reduced at some cost to performance
- on metadata intensive workloads. The logbsize option below
+ on metadata intensive workloads. The ``logbsize`` option below
controls the size of each buffer and so is also relevant to
this case.
and 32768 (32k). Valid sizes for version 2 logs also
include 65536 (64k), 131072 (128k) and 262144 (256k). The
logbsize must be an integer multiple of the log
- stripe unit configured at mkfs time.
+ stripe unit configured at **mkfs(8)** time.
The default value for for version 1 logs is 32768, while the
default value for version 2 logs is MAX(32768, log_sunit).
noalign
Data allocations will not be aligned at stripe unit
boundaries. This is only relevant to filesystems created
- with non-zero data alignment parameters (sunit, swidth) by
- mkfs.
+ with non-zero data alignment parameters (``sunit``, ``swidth``) by
+ **mkfs(8)**.
norecovery
The filesystem will be mounted without running log recovery.
If the filesystem was not cleanly unmounted, it is likely to
- be inconsistent when mounted in "norecovery" mode.
+ be inconsistent when mounted in ``norecovery`` mode.
Some files or directories may not be accessible because of this.
- Filesystems mounted "norecovery" must be mounted read-only or
+ Filesystems mounted ``norecovery`` must be mounted read-only or
the mount will fail.
nouuid
Don't check for double mounted file systems using the file
- system uuid. This is useful to mount LVM snapshot volumes,
- and often used in combination with "norecovery" for mounting
+ system ``uuid``. This is useful to mount LVM snapshot volumes,
+ and often used in combination with ``norecovery`` for mounting
read-only snapshots.
noquota
uquota/usrquota/uqnoenforce/quota
User disk quota accounting enabled, and limits (optionally)
- enforced. Refer to xfs_quota(8) for further details.
+ enforced. Refer to **xfs_quota(8)** for further details.
gquota/grpquota/gqnoenforce
Group disk quota accounting enabled and limits (optionally)
- enforced. Refer to xfs_quota(8) for further details.
+ enforced. Refer to **xfs_quota(8)** for further details.
pquota/prjquota/pqnoenforce
Project disk quota accounting enabled and limits (optionally)
- enforced. Refer to xfs_quota(8) for further details.
+ enforced. Refer to **xfs_quota(8)** for further details.
sunit=value and swidth=value
Used to specify the stripe unit and width for a RAID device
block units. These options are only relevant to filesystems
that were created with non-zero data alignment parameters.
- The sunit and swidth parameters specified must be compatible
+ The ``sunit`` and ``swidth`` parameters specified must be compatible
with the existing filesystem alignment characteristics. In
- general, that means the only valid changes to sunit are
- increasing it by a power-of-2 multiple. Valid swidth values
- are any integer multiple of a valid sunit value.
+ general, that means the only valid changes to ``sunit`` are
+ increasing it by a power-of-2 multiple. Valid ``swidth`` values
+ are any integer multiple of a valid ``sunit`` value.
Typically the only time these mount options are necessary if
after an underlying RAID device has had it's geometry
Deprecated Mount Options
========================
+=========================== ================
Name Removal Schedule
- ---- ----------------
+=========================== ================
+=========================== ================
Removed Mount Options
=====================
+=========================== =======
Name Removed
- ---- -------
+=========================== =======
delaylog/nodelaylog v4.0
ihashsize v4.0
irixsgid v4.0
osyncisdsync/osyncisosync v4.0
barrier v4.19
nobarrier v4.19
-
+=========================== =======
sysctls
=======
fs.xfs.inherit_sync (Min: 0 Default: 1 Max: 1)
Setting this to "1" will cause the "sync" flag set
- by the xfs_io(8) chattr command on a directory to be
+ by the **xfs_io(8)** chattr command on a directory to be
inherited by files in that directory.
fs.xfs.inherit_nodump (Min: 0 Default: 1 Max: 1)
Setting this to "1" will cause the "nodump" flag set
- by the xfs_io(8) chattr command on a directory to be
+ by the **xfs_io(8)** chattr command on a directory to be
inherited by files in that directory.
fs.xfs.inherit_noatime (Min: 0 Default: 1 Max: 1)
Setting this to "1" will cause the "noatime" flag set
- by the xfs_io(8) chattr command on a directory to be
+ by the **xfs_io(8)** chattr command on a directory to be
inherited by files in that directory.
fs.xfs.inherit_nosymlinks (Min: 0 Default: 1 Max: 1)
Setting this to "1" will cause the "nosymlinks" flag set
- by the xfs_io(8) chattr command on a directory to be
+ by the **xfs_io(8)** chattr command on a directory to be
inherited by files in that directory.
fs.xfs.inherit_nodefrag (Min: 0 Default: 1 Max: 1)
Setting this to "1" will cause the "nodefrag" flag set
- by the xfs_io(8) chattr command on a directory to be
+ by the **xfs_io(8)** chattr command on a directory to be
inherited by files in that directory.
fs.xfs.rotorstep (Min: 1 Default: 1 Max: 256)
-error handlers:
Defines the behavior for a specific error.
-The filesystem behavior during an error can be set via sysfs files. Each
+The filesystem behavior during an error can be set via ``sysfs`` files. Each
error handler works independently - the first condition met by an error handler
for a specific class will cause the error to be propagated rather than reset and
retried.
handler configurations.
Note: there is no guarantee that fail_at_unmount can be set while an
- unmount is in progress. It is possible that the sysfs entries are
+ unmount is in progress. It is possible that the ``sysfs`` entries are
removed by the unmounting filesystem before a "retry forever" error
handler configuration causes unmount to hang, and hence the filesystem
must be configured appropriately before unmount begins to prevent
Each filesystem has specific error class handlers that define the error
propagation behaviour for specific errors. There is also a "default" error
handler defined, which defines the behaviour for all errors that don't have
-specific handlers defined. Where multiple retry constraints are configuredi for
+specific handlers defined. Where multiple retry constraints are configured for
a single error, the first retry configuration that expires will cause the error
to be propagated. The handler configurations are found in the directory:
Setting the value to "N" (where 0 < N < Max) will allow XFS to retry the
operation for up to "N" seconds before propagating the error.
-Note: The default behaviour for a specific error handler is dependent on both
+**Note:** The default behaviour for a specific error handler is dependent on both
the class and error context. For example, the default values for
"metadata/ENODEV" are "0" rather than "-1" so that this error handler defaults
to "fail immediately" behaviour. This is done because ENODEV is a fatal,
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