=========================================================
ϡ
linux-2.6.29/Documentation/filesystems/xfs.txt 
Ǥ
Ρ JF ץ < http://www.linux.or.jp/JF/ >
  2009/03/28
  Seiji Kaneko < skaneko at mbn dot or dot jp >
  Nobumitsu Takei < takei at webmaster dor gr dot jp >
=========================================================
#The SGI XFS Filesystem
SGI XFS ե륷ƥ
======================

#XFS is a high performance journaling filesystem which originated
#on the SGI IRIX platform.  It is completely multi-threaded, can
#support large files and large filesystems, extended attributes,
#variable block sizes, is extent based, and makes extensive use of
#Btrees (directories, extents, free space) to aid both performance
#and scalability.
XFS Ϲǽʥ㡼ʥ󥰥ե륷ƥǡSGI IRIX ץåȥե
ͳ褹ΤǤ
ϴ˥ޥåбƤꡢʥեȵʥե륷
ƥξбĥȥӥ塼Ȥб֥åѤʥե
ƥǤꡢƥȥ١ǤꡢB-tree (ǥ쥯ȥꡢƥȡ
ΰ) ¿ѤǼƤޤǽȳĥξ
Ǥ

#Refer to the documentation at http://oss.sgi.com/projects/xfs/
#for further details.  This implementation is on-disk compatible
#with the IRIX version of XFS.
ܺ٤ˤĤƤϡhttp://oss.sgi.com/projects/xfs/ ˤʸ򻲹
ˤƤμϡǥ IRIX Ǥ XFS ˸ߴȤʤäƤޤ


#Mount Options
ޥȥץ
=============

#When mounting an XFS filesystem, the following options are accepted.
XFS ե륷ƥޥȤݤˤϡʲΥץդޤ

  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.
       ٱ񤭹ߤǤγƻˡХåե I/O end-of-file ץꥢ
       󥵥ꤷޤɸͤ 64KiB Ǥͭͤϥڡ
       (̾ 4KiB)  2 Ѿܤǡ 1GiB Ǥ

  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.
	Υץϡ饤ĥȥӥ塼Ȥǥ˳Ǽ
	ˡˡֲǽ⤤ѹäưͭȤ뤫̵
	Ȥ뤫ꤹΤǤͤϡǥΥǡθߴ
	Τ̵ˤʤäƤޤ
	Υץλˤ뿷 (ǥ) ǽ˻Ѥ
	줿ݤ (ĥȥӥ塼Ȥ򥻥åȤ뤤Ϻ뤳Ȥˤä)
	ǥΥѡ֥åΥեӥåϡѤƤ
	եޥåȤȿǤ褦ޤ

  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.
       㡼ʥ̤񤭹ߤΥƥѴν񤭹ߤФ롢֥
       쥤饤ȥХꥢͭˤޤ
       Υץϡ饤ȥХꥢ򥵥ݡȤǥХǡɥ饤֥
       񤭹ߥåͭˤǤ褦ˤޤ

  dmapi
#	Enable the DMAPI (Data Management API) event callouts.
#	Use with the "mtpt" option.
        DMAPI (Data Management API) ٥ȵưͭޤ
        "mtpt" ץȹ碌ѤƤ

#  grpid/bsdgroups and nogrpid/sysvgroups
  grpid/bsdgroups  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.
	ΥץϿ˺줿եΥ롼 ID ꤷ
	grpid ꤵƤˤϡ줿եΤǥ
	ȥ group ID ѤޤꤵƤʤ () 
	ϡsetgid ӥåȤǥ쥯ȥꤵƤ (ξ
	Ͽƥǥ쥯ȥ gid Ȥ졢ޤоݤǥ쥯ȥä
	ˤϡsetgid ӥåȤåȤޤ)ץ fsgid Ȥ
	

  ihashsize=value
#	In memory inode hashes have been removed, so this option has
#	no function as of August 2007. Option is deprecated.
         inode ϥå夬줿ᡢΥץ 2007 ǯ
        8 ʹ߲⤷ޤ󡣥ץѻͽǤ

  ikeep/noikeep
#	When ikeep is specified, XFS does not delete empty inode clusters
#	and keeps them around on disk. ikeep is the traditional XFS
#	behaviour. When noikeep is specified, empty inode clusters
#	are returned to the free space pool. The default is noikeep for
#	non-DMAPI mounts, while ikeep is the default when DMAPI is in use.
	ikeep ꤵƤ硢XFS ϶ inode 饹
	ǥݻ³ޤikeep Ͻ XFS εưǤnoikeep
	ꤵ줿ˤϡ inode 饹ϥե꡼ڡס
	ᤵޤͤ DMAPI ʤΥޥȤǤ noikeep ǡDMAPI
	ѤƤ ikeep Ǥ

  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.
	XFS ե륷ƥΤɤΰ֤ˤǤ inode Ƥ褤Ȥ
	ؼޤ inode ֹ椬 32 ӥåκ (i.e. 2^31) 
	ʾˤʤäƤɤȤޤߤޤεǽϽȤθߴΤ
	󶡤줿ΤǤ礭 inode ֹ򰷤ʤХååץ
	ꥱ򵯤Τޤ

  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.
	nolargeio ꤵ줿ϡstat(2) 𤵤Ŭ I/O 
	st_blocksize ϡ桼ץꥱ󤬸Ψΰɤߡ񤭡
	I/O 򤱤褦ǽʸ¤꾮ޤlargeio ꤵ줿
	硢swidth ꤵ줿ե륷ƥǤϡst_blocksize ˤ 
	swidth  (Хñ) ֤ޤե륷ƥ swidth 
	꤬ʤallocsize λ꤬硢allocsize  (Хñ)
	֤ޤ
	ɤΥץꤵƤʤ硢ե륷ƥ 
	nolargeio ꤵƤƱưԤʤޤ

  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 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
#	and their associated control structures.
	ΥХåեοꤷޤͭͤ 2  8 ޤǤ
		ͤϡ֥å 64KiB ξե륷ƥढ
	 8 Хåեǡ֥å 32KiB ξե륷ƥढ
	 4 Хåե֥å 16KiB ξե륷ƥढ 
	3 ХåեǡʳιǤ 2 ХåեǤХåեο
	ȤˤäưٴĶǤǽ夷ޤɲäΥХ
	եȴϢ湽¤ΤʬΥ񤷤ޤ

  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
#	65536 (64k), 131072 (128k) and 262144 (256k).
#	The default value for machines with more than 32MiB of memory
#	is 32768, machines with less memory use 16384 by default.
	ΥХåեΥꤷޤϥХñ̤ǻ
	ꤹ뤫"k" եåդƥХñ̤ǻꤹ뤫Ǥ
	С 1 ȥС 2 ͭʥ 16384(16k)  
	32768(32k) ǤС 2 ǤϹ 65536 (64k), 131072 
	(128k)  262144 (256k) Ǥޤ32MiB ʾΥĥ
	δͤ 32768 ǡʲΥޥǤ 16384 Ǥ

  logdev=device and rtdev=device
#	Use an external log (metadata journal) and/or real-time device.
#	An XFS filesystem has up to three parts: a data section, a log
#	section, and a real-time section.  The real-time section is
#	optional, and the log section can be separate from the data
#	section or contained within it.
	 (᥿ǡ㡼ʥ) ޤ/ӳꥢ륿ǥХ
	ѤޤXFS ե륷ƥϻĤʬ (ǡ
	ꥢ륿) ǤƤޤꥢ륿ϥץǡ
	ϥǡʬΥ뤳Ȥ⡢˴ޤ뤳ȤǤޤ

  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.
        "dmapi" ץȹ碌Ѥޤǻꤷͤ DMAPI ޥ
        ȥ٥Ȥ˴ޤޤޤͤϻѤޥȥݥȤμ¥ѥ
        ˤ٤Ǥ

  noalign
#	Data allocations will not be aligned at stripe unit boundaries.
        ǡƻˡȥ饤ñ̤ζ󤹤Ԥʤޤ
        

  noatime
#	Access timestamps are not updated when a file is read.
        եɤ߹߻ˡॹפ򹹿ޤ

  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.
#	Some files or directories may not be accessible because of this.
#	Filesystems mounted "norecovery" must be mounted read-only or
#	the mount will fail.
	ե륷ƥꥫХ¹Ԥʤ˥ޥȤޤե륷
	ƥब꡼˥ޥȤƤʤ硢norecovery ⡼ɤ
	ޥȤˤ礬ǽ⤤Ǥ礦Υե
	ǥ쥯ȥˡΤȤͳǥǤʤΤޤ
	norecovery ǥޥȤե륷ƥɤ߽ФΤߤǥޥ
	ȤʤФޤ󡣤ʤХޥȤϼԤޤ

  nouuid
#	Don't check for double mounted file systems using the file system uuid.
#	This is useful to mount LVM snapshot volumes.
	ե륷ƥ uuid Ѥե륷ƥ¿ťޥȥ
	Ԥʤޤ󡣤 LVM ʥåץåȥܥ塼ޥȤ
	Ǥ

  osyncisosync
#	Make O_SYNC writes implement true O_SYNC.  WITHOUT this option,
#	Linux XFS behaves as if an "osyncisdsync" option is used,
#	which will make writes to files opened with the O_SYNC flag set
#	behave as if the O_DSYNC flag had been used instead.
#	This can result in better performance without compromising
#	data safety.
#	However if this option is not in effect, timestamp updates from
#	O_SYNC writes can be lost if the system crashes.
#	If timestamp updates are critical, use the osyncisosync option.
	O_SYNC 񤭹ߤμ򡢻̤ O_SYNC εưˤޤΥ
	ץꤷʤ硢Linux XFS  osyncisdsync ץ
	ꤵƤ롢Ĥޤ O_SYNC ե饰դ open 줿ե
	ϡO_DSYNC ꤵ줿ΤȤưޤ
	ˤꡢǡΰϵˤʤ餺ǽ夷ޤ
	âΥץˤꡢO_SYNC 񤭹ߤǹԤʤä
	timestamp ϥƥ९å˼ޤ⤷ timestamp
	ɬܤʤСosyncisosync ץȤäƤ

  uquota/usrquota/uqnoenforce/quota
#	User disk quota accounting enabled, and limits (optionally)
#	enforced.  Refer to xfs_quota(8) for further details.
	桼ǥƥ󥰤ͭˤ (ץ)
	ŬѤޤܺ٤ xfs_quota(8) 򻲾Ȥ

  gquota/grpquota/gqnoenforce
#	Group disk quota accounting enabled and limits (optionally)
#	enforced.  Refer to xfs_quota(8) for further details.
	롼ץǥƥ󥰤ͭˤ (ץ
	) ŬѤޤܺ٤ xfs_quota(8) 򻲾Ȥ

  pquota/prjquota/pqnoenforce
#	Project disk quota accounting enabled and limits (optionally)
#	enforced.  Refer to xfs_quota(8) for further details.
	ץȥǥƥ󥰤ͭˤ (
	) ŬѤޤܺ٤ xfs_quota(8) 򻲾Ȥ

  sunit=value and swidth=value
#	Used to specify the stripe unit and width for a RAID device or
#	a stripe volume.  "value" must be specified in 512-byte block
#	units.
#	If this option is not specified and the filesystem was made on
#	a stripe volume or the stripe width or unit were specified for
#	the RAID device at mkfs time, then the mount system call will
#	restore the value from the superblock.  For filesystems that
#	are made directly on RAID devices, these options can be used
#	to override the information in the superblock if the underlying
#	disk layout changes after the filesystem has been created.
#	The "swidth" option is required if the "sunit" option has been
#	specified, and must be a multiple of the "sunit" value.
	RAID ǥХ䥹ȥ饤ץܥ塼Ρȥ饤ץ˥åñ
	ꤷޤvalue  512-byte ֥åñ̤ǻꤷޤ
	Υץ󤬻ꤵƤ餺ե륷ƥबȥ饤ץܥ
	塼˺Ƥ硢ޤ mkfs ˥ȥ饤ޤϥ
	˥åȤꤵƤϡޥȥƥॳˤꥹѡ
	֥åꤽͤФޤ
	RAID ǥХľܺ줿ե륷ƥǤϡΥǥ
	쥤Ȥե륷ƥѲ硢Υץ
	Ȥäơѡ֥åξ񤭤뤳ȤǤޤ
	sunit ץ󤬻ꤵƤ硢swidth ץλɬ
	ܤǡ sunit ܿǤʤФޤ

  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.
	ߤ EOF Ķƽ񤭹ߤԤʤȤƤꡢե뤬ȥ饤
	Ĺ礭硢ǡƤȥ饤ĹޤǤ˳ĥ
	ޤ


#sysctls
sysctl 
=========

#The following sysctls are available for the XFS filesystem:
XFS ե륷ƥǤϡʲ sysctl 󶡤Ƥޤ

  fs.xfs.stats_clear		(Min: 0  Default: 0  Max: 1)
#	Setting this to "1" clears accumulated XFS statistics
#	in /proc/fs/xfs/stat.  It then immediately resets to "0".
        "1" ˤ뤳Ȥˤꡢޤ /proc/fs/xfs/stat 
       ˺μ褵Ƥ XFS ׾򥯥ꥢޤ
       ľˤΥӥåȤ "0" ˥ꥻåȤޤ

  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
#  	do some processing on unlinked inodes.
	xfssyncd åɤ᥿ǡǥǤФֳִ֡
	ΥåɤưǤФunlink 줿 inode Ф¿
	νԤޤ

  fs.xfs.xfsbufd_centisecs	(Min: 50  Default: 100	Max: 3000)
#	The interval at which xfsbufd scans the dirty metadata buffers list.
        xfsbufd ƥ᥿ǡХåեꥹȤ򥹥󤹤ֳ֤Ǥ

  fs.xfs.age_buffer_centisecs	(Min: 100  Default: 1500  Max: 720000)
#	The age at which xfsbufd flushes dirty metadata buffers to disk.
        xfsbufd ƥ᥿ǡХåեꥹȤǥǤФֳ
        Ǥ

  fs.xfs.error_level		(Min: 0  Default: 3  Max: 11)
#	A volume knob for error reporting when internal errors occur.
#	This will generate detailed messages & backtraces for filesystem
#	shutdowns, for example.  Current threshold values are:
        顼ȯȤΥ顼βĴǤˤꡢ
        ٤ʥåȥե륷ƥॷåȥΥХåȥ졼ʤ
        ޤߤΤͤϰʲ̤Ǥ

		XFS_ERRLEVEL_OFF:       0
		XFS_ERRLEVEL_LOW:       1
		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;
#	AND together the tags which represent errors which should cause panics:
       BUG() ؿƤ֤ȤˤꡢΥ顼ȯޤ
       Ϳͤϥӥåȥޥˤä졢顼򼨤ʣȤ
       Ȥˤ panic ȯϤǤ

		XFS_NO_PTAG                     0
		XFS_PTAG_IFLUSH                 0x00000001
		XFS_PTAG_LOGRES                 0x00000002
		XFS_PTAG_AILDELETE              0x00000004
		XFS_PTAG_ERROR_REPORT           0x00000008
		XFS_PTAG_SHUTDOWN_CORRUPT       0x00000010
		XFS_PTAG_SHUTDOWN_IOERROR       0x00000020
		XFS_PTAG_SHUTDOWN_LOGERROR      0x00000040

#	This option is intended for debugging only.
        ΥץϥǥХåΤߤѤ뤳ȤտޤƤޤ

  fs.xfs.irix_symlink_mode	(Min: 0  Default: 0  Max: 1)
#	Controls whether symlinks are created with mode 0777 (default)
#	or whether their mode is affected by the umask (irix mode).
	ܥå󥯤⡼ 777 () Ǻ뤫umask αƶ
	 (Irix ⡼) 椷ޤ

  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
#	is set.
	SGID ǥ쥯ȥΥե椷ޤ
	եΥ롼 ID ¸롼 ID Ȥ⡢ƥǥ쥯ȥ
	롼 ID Ȥפʤ硢irix_sgid_inherit ߴ sysctl 
	ꤷƤ硢ISGID ӥåȤϥꥢޤ

  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.
	ΥӥåȤ "1" ꤹ뤳Ȥˤꡢǥ쥯ȥФ xfs_io(8)
	chattr ޥɤѤ "sync" ե饰ꤷƤ硢ǥ쥯ȥ
	Υե "sync" °Ѥޤ

  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.
	ΥӥåȤ "1" ꤹ뤳Ȥˤꡢǥ쥯ȥФ xfs_io(8) 
	chattr ޥɤѤ "nodump" ե饰ꤷƤ硢ǥ쥯
	Υե "nodump" °Ѥޤ

  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.
	ΥӥåȤ "1" ˤ硢ǥ쥯ȥФ xfs_io(8) chattr 
	ޥɤѤ "noatime" ե饰ꤷƤ硢ǥ쥯ȥ
	Υե "noatime" °Ѥޤ

  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.
	ΥӥåȤ "1" ˤ硢ǥ쥯ȥФ xfs_io(8) chattr 
	ޥɤѤ "nosymlinks" ե饰ꤷƤ硢ǥ쥯ȥ
	Υե "nosymlinks" °Ѥޤ

  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.
	"inode32" ⡼ɻˡΥץϡ
	Υ󥰥롼פ˰ưˡĤΥ󥰥
	ǥԤʤեꤷޤϡ
	եΤΥƥȤγƻˡ
	󥰥롼״֤ư٤ĴΤΤΤǤ

