When mounting an XFS filesystem, the following options are accepted.
- biosize=size
- Sets the preferred buffered I/O size (default size is 64K).
- "size" must be expressed as the logarithm (base2) of the
- desired I/O size.
- Valid values for this option are 14 through 16, inclusive
- (i.e. 16K, 32K, and 64K bytes). On machines with a 4K
- pagesize, 13 (8K bytes) is also a valid size.
- The preferred buffered I/O size can also be altered on an
- individual file basis using the ioctl(2) system call.
+ allocsize=size
+ Sets the buffered I/O end-of-file preallocation size when
+ doing delayed allocation writeout (default size is 64KiB).
+ Valid values for this option are page size (typically 4KiB)
+ through to 1GiB, inclusive, in power-of-2 increments.
+
+ attr2/noattr2
+ The options enable/disable (default is disabled for backward
+ compatibility on-disk) 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 (by setting or
+ removing extended attributes) the on-disk superblock feature
+ bit field will be updated to reflect this format being in use.
+
+ barrier
+ Enables the use of block layer write barriers for writes into
+ the journal and unwritten extent conversion. This allows for
+ drive level write caching to be enabled, for devices that
+ support write barriers.
+
+ dmapi
+ Enable the DMAPI (Data Management API) event callouts.
+ Use with the "mtpt" option.
+
+ grpid/bsdgroups and nogrpid/sysvgroups
+ These options define what group ID a newly created file gets.
+ When grpid is set, it takes the group ID of the directory in
+ which it is created; otherwise (the default) 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 a directory itself.
+
+ ihashsize=value
+ Sets the number of hash buckets available for hashing the
+ in-memory inodes of the specified mount point. If a value
+ of zero is used, the value selected by the default algorithm
+ will be displayed in /proc/mounts.
ikeep/noikeep
When inode clusters are emptied of inodes, keep them around
and is still the default for now. Using the noikeep option,
inode clusters are returned to the free space pool.
+ inode64
+ 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. This is
+ provided for backwards compatibility, but causes problems for
+ backup applications that cannot handle large inode numbers.
+
+ 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 user
+ applications to avoid inefficient read/modify/write I/O.
+ If "largeio" specified, a filesystem that has 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.
+ If neither of these two options are specified, then filesystem
+ will behave as if "nolargeio" was specified.
+
logbufs=value
Set the number of in-memory log buffers. Valid numbers range
from 2-8 inclusive.
The default value is 8 buffers for filesystems with a
- blocksize of 64K, 4 buffers for filesystems with a blocksize
- of 32K, 3 buffers for filesystems with a blocksize of 16K
+ blocksize of 64KiB, 4 buffers for filesystems with a blocksize
+ of 32KiB, 3 buffers for filesystems with a blocksize of 16KiB
and 2 buffers for all other configurations. Increasing the
number of buffers may increase performance on some workloads
at the cost of the memory used for the additional log buffers
logbsize=value
Set the size of each in-memory log buffer.
Size may be specified in bytes, or in kilobytes with a "k" suffix.
- Valid sizes for version 1 and version 2 logs are 16384 (16k) and
- 32768 (32k). Valid sizes for version 2 logs also include
+ Valid sizes for version 1 and version 2 logs are 16384 (16k) and
+ 32768 (32k). Valid sizes for version 2 logs also include
65536 (64k), 131072 (128k) and 262144 (256k).
- The default value for machines with more than 32MB of memory
+ The default value for machines with more than 32MiB of memory
is 32768, machines with less memory use 16384 by default.
logdev=device and rtdev=device
optional, and the log section can be separate from the data
section or contained within it.
+ mtpt=mountpoint
+ Use with the "dmapi" option. The value specified here will be
+ included in the DMAPI mount event, and should be the path of
+ the actual mountpoint that is used.
+
noalign
Data allocations will not be aligned at stripe unit boundaries.
O_SYNC writes can be lost if the system crashes.
If timestamp updates are critical, use the osyncisosync option.
- quota/usrquota/uqnoenforce
+ uquota/usrquota/uqnoenforce/quota
User disk quota accounting enabled, and limits (optionally)
- enforced.
+ enforced. Refer to xfs_quota(8) for further details.
- grpquota/gqnoenforce
+ gquota/grpquota/gqnoenforce
Group disk quota accounting enabled and limits (optionally)
- enforced.
+ 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.
sunit=value and swidth=value
Used to specify the stripe unit and width for a RAID device or
The "swidth" option is required if the "sunit" option has been
specified, and must be a multiple of the "sunit" value.
+ swalloc
+ Data allocations will be rounded up to stripe width boundaries
+ when the current end of file is being extended and the file
+ size is larger than the stripe width size.
+
+
sysctls
=======
The following sysctls are available for the XFS filesystem:
fs.xfs.stats_clear (Min: 0 Default: 0 Max: 1)
- Setting this to "1" clears accumulated XFS statistics
+ Setting this to "1" clears accumulated XFS statistics
in /proc/fs/xfs/stat. It then immediately resets to "0".
-
+
fs.xfs.xfssyncd_centisecs (Min: 100 Default: 3000 Max: 720000)
The interval at which the xfssyncd thread flushes metadata
out to disk. This thread will flush log activity out, and
XFS_ERRLEVEL_HIGH: 5
fs.xfs.panic_mask (Min: 0 Default: 0 Max: 127)
- Causes certain error conditions to call BUG(). Value is a bitmask;
+ Causes certain error conditions to call BUG(). Value is a bitmask;
AND together the tags which represent errors which should cause panics:
-
+
XFS_NO_PTAG 0
XFS_PTAG_IFLUSH 0x00000001
XFS_PTAG_LOGRES 0x00000002
XFS_PTAG_SHUTDOWN_IOERROR 0x00000020
XFS_PTAG_SHUTDOWN_LOGERROR 0x00000040
- This option is intended for debugging only.
+ This option is intended for debugging only.
fs.xfs.irix_symlink_mode (Min: 0 Default: 0 Max: 1)
Controls whether symlinks are created with mode 0777 (default)
fs.xfs.irix_sgid_inherit (Min: 0 Default: 0 Max: 1)
Controls files created in SGID directories.
If the group ID of the new file does not match the effective group
- ID or one of the supplementary group IDs of the parent dir, the
- ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl
+ ID or one of the supplementary group IDs of the parent dir, the
+ ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl
is set.
fs.xfs.restrict_chown (Min: 0 Default: 1 Max: 1)
Controls whether unprivileged users can use chown to "give away"
a file to another user.
- fs.xfs.inherit_sync (Min: 0 Default: 1 Max 1)
- Setting this to "1" will cause the "sync" flag set
- by the chattr(1) command on a directory to be
+ 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
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 chattr(1) command on a directory to be
+ 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
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 chattr(1) command on a directory to be
+ 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
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
+ inherited by files in that directory.
+
+ fs.xfs.rotorstep (Min: 1 Default: 1 Max: 256)
+ In "inode32" allocation mode, this option determines how many
+ files the allocator attempts to allocate in the same allocation
+ group before moving to the next allocation group. The intent
+ is to control the rate at which the allocator moves between
+ allocation groups when allocating extents for new files.
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