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authorNathan Scott <nathans@sgi.com>2005-11-03 13:46:43 +1100
committerNathan Scott <nathans@sgi.com>2005-11-03 13:46:43 +1100
commitfc97bbf35d925b3e18a6a31d577552825146952e (patch)
tree2c70d450bd853132051a9b837c6bf9a59f78f050
parentbf6f05aa0bb6f1fe9a9ce35287678c3916bddfef (diff)
downloadlinux-linaro-stable-fc97bbf35d925b3e18a6a31d577552825146952e.tar.gz
[XFS] Update XFS documentation.
Signed-off-by: Nathan Scott <nathans@sgi.com>
-rw-r--r--Documentation/filesystems/xfs.txt142
1 files changed, 108 insertions, 34 deletions
diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt
index c7d5d0c7067d..74aeb142ae5f 100644
--- a/Documentation/filesystems/xfs.txt
+++ b/Documentation/filesystems/xfs.txt
@@ -19,15 +19,43 @@ Mount Options
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
@@ -35,12 +63,31 @@ When mounting an XFS filesystem, the following options are accepted.
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
@@ -49,10 +96,10 @@ When mounting an XFS filesystem, the following options are accepted.
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
@@ -62,6 +109,11 @@ When mounting an XFS filesystem, the following options are accepted.
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.
@@ -91,13 +143,17 @@ When mounting an XFS filesystem, the following options are accepted.
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
@@ -113,15 +169,21 @@ When mounting an XFS filesystem, the following options are accepted.
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
@@ -143,9 +205,9 @@ The following sysctls are available for the XFS filesystem:
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
@@ -155,7 +217,7 @@ The following sysctls are available for the XFS filesystem:
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)
@@ -164,25 +226,37 @@ The following sysctls are available for the XFS filesystem:
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.