.\" 970114, aeb: xiafs and ext are dead; romfs is new
.\" 970623, aeb: -F option
.\" 970914, reg: -s option
+.\" 981111, K.Garloff: /etc/filesystems
+.\" 990111, aeb: documented /sbin/mount.smbfs
+.\" 990730, Yann Droneaud <lch@multimania.com>: updated page
+.\" 991214, Elrond <Elrond@Wunder-Nett.org>: added some docs on devpts
+.\" 010714, Michael K. Johnson <johnsonm@redhat.com> added -O
+.\" 010725, Nikita Danilov <NikitaDanilov@Yahoo.COM>: reiserfs options
+.\" 011124, Karl Eichwalder <ke@gnu.franken.de>: tmpfs options
.\"
.TH MOUNT 8 "14 September 1997" "Linux 2.0" "Linux Programmer's Manual"
.SH NAME
mount \- mount a file system
.SH SYNOPSIS
-.BI "mount [\-hV]"
+.BI "mount [\-lhV]"
.LP
-.BI "mount \-a [\-fFnrsvw] [\-t " vfstype ]
+.BI "mount \-a [\-fFnrsvw] [\-t " vfstype "] [\-O " optlist ]
.br
.BI "mount [\-fnrsvw] [\-o " options " [,...]] " "device " | " dir"
.br
.RE
prints a version string; and just
.RS
-.BI "mount [-t" " type" ]
+.BI "mount [-l] [-t" " type" ]
.RE
lists all mounted file systems (of type
-.IR type )
-- see below.
+.IR type ).
+The option \-l adds the (ext2, ext3 and XFS) labels in this listing.
+See below.
+
+.\" In fact since 2.3.99. At first the syntax was mount -t bind.
+Since Linux 2.4.0 it is possible to remount part of the
+file hierarchy somewhere else. The call is
+.RS
+.br
+.B "mount --bind olddir newdir"
+.RE
+After this call the same contents is accessible in two places.
+
+This call attaches only (part of) a single filesystem, not possible
+submounts. The entire file hierarchy including submounts is attached
+a second place using
+.RS
+.br
+.B "mount --rbind olddir newdir"
+.RE
+.\" available since Linux 2.4.11.
+
+Since Linux 2.5.1 it is possible to atomically move a subtree
+to another place. The call is
+.RS
+.br
+.B "mount --move olddir newdir"
+.RE
The
.I proc
.I device
may look like
.IR knuth.cwi.nl:/dir .
+It is possible to indicate a block special device using its
+volume label or UUID (see the \-L and \-U options below).
The file
.I /etc/fstab
(i) The command
.RS
.br
-.BI "mount \-a [-t" " type" ]
+.BI "mount \-a [\-t " type "] [\-O " optlist ]
.RE
(usually given in a bootscript) causes all file systems mentioned in
.I fstab
-(of the proper type) to be mounted as indicated, except for those
-whose line contains the
+(of the proper type and/or having or not having the proper options)
+to be mounted as indicated, except for those whose line contains the
.B noauto
keyword. Adding the
.B \-F
.RE
For more details, see
.BR fstab (5).
+Only the user that mounted a filesystem can unmount it again.
+If any user should be able to unmount, then use
+.B users
+instead of
+.B user
+in the
+.I fstab
+line.
+The
+.B owner
+option is similar to the
+.B user
+option, with the restriction that the user must be the owner
+of the special file. This may be useful e.g. for
+.I /dev/fd
+if a login script makes the console user owner of this device.
The programs
.B mount
If no arguments are given to
.BR mount ,
this list is printed.
+
When the
.I proc
filesystem is mounted (say at
by a symbolic link to
.IR /proc/mounts ,
but some information is lost that way, and in particular
-working with the loop device will be less convenient.
+working with the loop device will be less convenient,
+and using the "user" option will fail.
.SH OPTIONS
The full set of options used by an invocation of
command is trying to do. It can also be used to add entries for devices
that were mounted earlier with the -n option.
.TP
+.B \-i
+Don't call the /sbin/mount.<filesystem> helper even if it exists.
+.TP
+.B \-l
+Add the ext2, ext3 and XFS labels in the mount output. Mount must have
+permission to read the disk device (e.g. be suid root) for this to work.
+One can set such a label for ext2 or ext3 using the
+.BR e2label (8)
+utility, or for XFS using
+.BR xfs_admin (8).
+.TP
.B \-n
Mount without writing in
.IR /etc/mtab .
.I /etc
is on a read-only file system.
.TP
+.BI \-p " num"
+In case of a loop mount with encryption, read the passphrase from
+file descriptor
+.I num
+instead of from the terminal.
+.TP
.B \-s
Tolerate sloppy mount options rather than failing. This will ignore
mount options not supported by a filesystem type. Not all filesystems
Mount the file system read/write. This is the default. A synonym is
.BR "\-o rw" .
.TP
+.BI \-L " label"
+Mount the partition that has the specified
+.IR label .
+.TP
+.BI \-U " uuid"
+Mount the partition that has the specified
+.IR uuid .
+These two options require the file
+.I /proc/partitions
+(present since Linux 2.1.116) to exist.
+.TP
.BI \-t " vfstype"
The argument following the
.B \-t
is used to indicate the file system type. The file system types which are
-currently supported are listed in
-.IR linux/fs/filesystems.c :
-.IR minix ", " ext ", " ext2 ", " xiafs ", " hpfs ,
-.IR msdos ", " umsdos ", " vfat ,
-.IR proc ", " nfs ", " iso9660 ", " smbfs ", " ncpfs ,
-.IR affs ", " ufs ", " romfs ,
-.IR sysv ", " xenix ", " coherent .
-Note that the last three are equivalent and that
+currently supported are:
+.IR adfs ,
+.IR affs ,
+.IR autofs ,
+.IR coda ,
+.IR coherent ,
+.IR cramfs ,
+.IR devpts ,
+.IR efs ,
+.IR ext ,
+.IR ext2 ,
+.IR ext3 ,
+.IR hfs ,
+.IR hpfs ,
+.IR iso9660 ,
+.IR jfs ,
+.IR minix ,
+.IR msdos ,
+.IR ncpfs ,
+.IR nfs ,
+.IR ntfs ,
+.IR proc ,
+.IR qnx4 ,
+.IR ramfs ,
+.IR reiserfs ,
+.IR romfs ,
+.IR smbfs ,
+.IR sysv ,
+.IR tmpfs ,
+.IR udf ,
+.IR ufs ,
+.IR umsdos ,
+.IR vfat ,
+.IR xenix ,
+.IR xfs ,
+.IR xiafs .
+Note that coherent, sysv and xenix are equivalent and that
.I xenix
and
.I coherent
.I xiafs
do not exist anymore.
+For most types all the
+.B mount
+program has to do is issue a simple
+.IR mount (2)
+system call, and no detailed knowledge of the filesystem type is required.
+For a few types however (like nfs, smbfs, ncpfs) ad hoc code is
+necessary. The nfs ad hoc code is built in, but smbfs and ncpfs
+have a separate mount program. In order to make it possible to
+treat all types in a uniform way, mount will execute the program
+.I /sbin/mount.TYPE
+(if that exists) when called with type
+.IR TYPE .
+Since various versions of the
+.I smbmount
+program have different calling conventions,
+.I /sbin/mount.smbfs
+may have to be a shell script that sets up the desired call.
+
The type
.I iso9660
is the default. If no
option is given, or if the
.B auto
type is specified, the superblock is probed for the filesystem type
-.RI ( minix ", " ext ", " ext2 ", " xiafs ", " iso9660 ", " romfs
+.RI ( adfs ,
+.IR bfs ,
+.IR cramfs ,
+.IR ext ,
+.IR ext2 ,
+.IR ext3 ,
+.IR hfs ,
+.IR hpfs ,
+.IR iso9660 ,
+.IR jfs ,
+.IR minix ,
+.IR ntfs ,
+.IR qnx4 ,
+.IR reiserfs ,
+.IR romfs ,
+.IR udf ,
+.IR ufs ,
+.IR vxfs ,
+.IR xfs ,
+.IR xiafs
are supported).
-If this probe fails and
-.I /proc/filesystems
-exists, then all of the filesystems listed there will be tried,
+If this probe fails, mount will try to read the file
+.IR /etc/filesystems ,
+or, if that does not exist,
+.IR /proc/filesystems .
+All of the filesystem types listed there will be tried,
except for those that are labeled "nodev" (e.g.,
+.IR devpts ,
.I proc
and
.IR nfs ).
+If
+.I /etc/filesystems
+ends in a line with a single * only, mount will read
+.I /proc/filesystems
+afterwards.
-Note that the
+The
.B auto
type may be useful for user-mounted floppies.
+Creating a file
+.I /etc/filesystems
+can be useful to change the probe order (e.g., to try vfat before msdos)
+or if you use a kernel module autoloader.
Warning: the probing uses a heuristic (the presence of appropriate `magic'),
-and could recognize the wrong filesystem type.
+and could recognize the wrong filesystem type, possibly with catastrophic
+consequences. If your data is valuable, don't ask
+.B mount
+to guess.
More than one type may be specified in a comma separated
list. The list of file system types can be prefixed with
.IR ext .
.RE
.TP
+.B \-O
+Used in conjunction with
+.BR \-a ,
+to limit the set of filesystems to which the
+.B \-a
+is applied. Like
+.B \-t
+in this regard except that it is useless except in the context of
+.BR \-a .
+For example, the command:
+.RS
+.RS
+.B "mount \-a \-O no_netdev"
+.RE
+mounts all file systems except those which have the option
+.I _netdev
+specified in the options field in the
+.I /etc/fstab
+file.
+
+It is different from
+.B \-t
+in that each option is matched exactly; a leading
+.B no
+at the beginning of one option does not negate the rest.
+
+The
+.B \-t
+and
+.B \-O
+options are cumulative in effect; that is, the command
+.RS
+.B "mount \-a \-t ext2 \-O _netdev"
+.RE
+mounts all ext2 filesystems with the _netdev option, not all filesystems
+that are either ext2 or have the _netdev option specified.
+.RE
+.TP
.B \-o
Options are specified with a
.B \-o
Some of these options are only useful when they appear in the
.I /etc/fstab
file. The following options apply to any file system that is being
-mounted:
+mounted (but not every file system actually honors them - e.g., the
+.B sync
+option today has effect only for ext2, ext3 and ufs):
.RS
.TP
.B async
.B exec
Permit execution of binaries.
.TP
+.B _netdev
+The filesystem resides on a device that requires network access
+(used to prevent the system from attempting to mount these filesystems
+until the network has been enabled on the system).
+.TP
.B noatime
Do not update inode access times on this file system (e.g, for faster
access on the news spool to speed up news servers).
.TP
.B nosuid
Do not allow set-user-identifier or set-group-identifier bits to take
-effect.
+effect. (This seems safe, but is in fact rather unsafe if you have
+suidperl(1) installed.)
.TP
.B nouser
Forbid an ordinary (i.e., non-root) user to mount the file system.
.B remount
Attempt to remount an already-mounted file system. This is commonly
used to change the mount flags for a file system, especially to make a
-readonly file system writeable.
+readonly file system writeable. It does not change device or mount point.
.TP
.B ro
Mount the file system read-only.
.B sync
All I/O to the file system should be done synchronously.
.TP
+.B dirsync
+All directory updates within the file system should be done synchronously.
+This affects the following system calls: creat, link, unlink, symlink,
+mkdir, rmdir, mknod and rename.
+.TP
.B user
-Allow an ordinary user to mount the file system. This option implies
-the options
+Allow an ordinary user to mount the file system.
+The name of the mounting user is written to mtab so that he can unmount
+the file system again.
+This option implies the options
.BR noexec ", " nosuid ", and " nodev
(unless overridden by subsequent options, as in the option line
.BR user,exec,dev,suid ).
+.TP
+.B users
+Allow every user to mount and unmount the file system.
+This option implies the options
+.BR noexec ", " nosuid ", and " nodev
+(unless overridden by subsequent options, as in the option line
+.BR users,exec,dev,suid ).
.RE
+.TP
+.B \-\-bind
+Remount a subtree somewhere else (so that its contents are available
+in both places). See above.
+.TP
+.B \-\-move
+Move a subtree to some other place. See above.
.SH "FILESYSTEM SPECIFIC MOUNT OPTIONS"
The following options apply only to certain file systems.
We sort them by file system. They all follow the
.B \-o
flag.
-
+.SH "Mount options for adfs"
+.TP
+\fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
+Set the owner and group of the files in the file system (default: uid=gid=0).
+.TP
+\fBownmask=\fP\fIvalue\fP and \fBothmask=\fP\fIvalue\fP
+Set the permission mask for ADFS 'owner' permissions and 'other' permissions,
+respectively (default: 0700 and 0077, respectively).
+See also
+.IR /usr/src/linux/Documentation/filesystems/adfs.txt .
.SH "Mount options for affs"
.TP
\fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
.TP
.BR grpquota " / " noquota " / " quota " / " usrquota
These options are accepted but ignored.
+(However, quota utilities may react to such strings in
+.IR /etc/fstab .)
.SH "Mount options for coherent"
None.
+.SH "Mount options for devpts"
+The devpts file system is a pseudo file system, traditionally mounted on
+.IR /dev/pts .
+In order to acquire a pseudo terminal, a process opens
+.IR /dev/ptmx ;
+the number of the pseudo terminal is then made available to the process
+and the pseudo terminal slave can be accessed as
+.IR /dev/pts/ <number>.
+.TP
+\fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
+This sets the owner or the group of newly created PTYs to
+the specified values. When nothing is specified, they will
+be set to the UID and GID of the creating process.
+For example, if there is a tty group with GID 5, then
+.B gid=5
+will cause newly created PTYs to belong to the tty group.
+.TP
+.BI mode= value
+Set the mode of newly created PTYs to the specified value.
+The default is 0600.
+A value of
+.B mode=620
+and
+.B gid=5
+makes "mesg y" the default on newly created PTYs.
+
.SH "Mount options for ext"
None.
Note that the `ext' file system is obsolete. Don't use it.
Set checking level. When at least one of these options is set (and
.B check=normal
is set by default) the inodes and blocks bitmaps are checked upon mount
-(which can take half a minute or so on a big disk).
+(which can take half a minute or so on a big disk, and is rather useless).
With strict checking, block deallocation checks that the block to free
is in the data zone.
.TP
.BR check=none " / " nocheck
-No checking is done.
+No checking is done. This is fast. Recent kernels do not have a
+check option anymore - checking with
+.BR e2fsck (8)
+is more meaningful.
.TP
.B debug
Print debugging info upon each (re)mount.
Instead of block 1, use block
.I n
as superblock. This could be useful when the filesystem has been damaged.
-Usually, copies of the superblock are found every 8192 blocks: in
-block 1, 8193, 16385, ...
-(Thus, one gets hundreds or even thousands of copies of the superblock
-on a big filesystem. I do not know of options to mke2fs that would
-cause fewer copies to be written.)
+(Earlier, copies of the superblock would be made every 8192 blocks: in
+block 1, 8193, 16385, ... (and one got hundreds or even thousands
+of copies on a big filesystem). Since version 1.08,
+.B mke2fs
+has a \-s (sparse superblock) option to reduce the number of backup
+superblocks, and since version 1.15 this is the default. Note
+that this may mean that ext2 filesystems created by a recent
+.B mke2fs
+cannot be mounted r/w under Linux 2.0.*.)
+The block number here uses 1k units. Thus, if you want to use logical
+block 32768 on a filesystem with 4k blocks, use "sb=131072".
.TP
.BR grpquota " / " noquota " / " quota " / " usrquota
These options are accepted but ignored.
+.TP
+.BR nouid32
+Disables 32-bit UIDs and GIDs. This is for interoperability with older
+kernels which only store and expect 16-bit values.
+
+
+.SH "Mount options for ext3"
+The `ext3' file system is version of the ext2 file system which has been
+enhanced with journalling. It supports the same options as ext2 as
+well as the following additions:
+.\" .TP
+.\" .BR abort
+.\" Mount the file system in abort mode, as if a fatal error has occurred.
+.TP
+.BR journal=update
+Update the ext3 file system's journal to the current format.
+.TP
+.BR journal=inum
+When a journal already exists, this option is ignored. Otherwise, it
+specifies the number of the inode which will represent the ext3 file system's
+journal file; ext3 will create a new journal, overwriting the old contents
+of the file whose inode number is
+.IR inum .
+.TP
+.BR noload
+Do not load the ext3 file system's journal on mounting.
+.TP
+.BR data=journal " / " data=ordered " / " data=writeback
+Specifies the journalling mode for file data. Metadata is always journaled.
+.RS
+.TP
+.B journal
+All data is committed into the journal prior to being written into the
+main file system.
+.TP
+.B ordered
+This is the default mode. All data is forced directly out to the main file
+system prior to its metadata being committed to the journal.
+.TP
+.B writeback
+Data ordering is not preserved - data may be written into the main
+file system after its metadata has been committed to the journal.
+This is rumoured to be the highest-throughput option. It guarantees
+internal file system integrity, however it can allow old data to appear
+in files after a crash and journal recovery.
+
.SH "Mount options for fat"
(Note:
.I fat
.I vfat
filesystems.)
.TP
-.BR blocksize=512 " / " blocksize=1024
+.BR blocksize=512 " / " blocksize=1024 " / " blocksize=2048
Set blocksize (default 512).
.TP
\fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
present). The default is the umask of the current process.
The value is given in octal.
.TP
+.BI dmask= value
+Set the umask applied to directories only.
+The default is the umask of the current process.
+The value is given in octal. Present since 2.5.43.
+.TP
+.BI fmask= value
+Set the umask applied to regular files only.
+The default is the umask of the current process.
+The value is given in octal. Present since 2.5.43.
+.TP
.BI check= value
Three different levels of pickyness can be chosen:
.RS
rejected. (+, =, spaces, etc.)
.RE
.TP
+.BI codepage= value
+Sets the codepage for converting to shortname characters on FAT
+and VFAT filesystems. By default, codepage 437 is used.
+.TP
.BR conv=b[inary] " / " conv=t[ext] " / " conv=a[uto]
The
.I fat
(fromdos/todos) is available.
.RE
.TP
+.BI cvf_format= module
+Forces the driver to use the CVF (Compressed Volume File) module
+.RI cvf_ module
+instead of auto-detection. If the kernel supports kmod, the
+cvf_format=xxx option also controls on-demand CVF module loading.
+.TP
+.BI cvf_option= option
+Option passed to the CVF module.
+.TP
.B debug
Turn on the
.I debug
printed (these data are also printed if the parameters appear to be
inconsistent).
.TP
-.BR fat=12 " / " fat=16
-Specify either a 12 bit fat or a 16 bit fat. This overrides
+.BR fat=12 " / " fat=16 " / " fat=32
+Specify a 12, 16 or 32 bit fat. This overrides
the automatic FAT type detection routine. Use with caution!
.TP
+.BI iocharset= value
+Character set to use for converting between 8 bit characters
+and 16 bit Unicode characters. The default is iso8859-1.
+Long filenames are stored on disk in Unicode format.
+.TP
.B quiet
Turn on the
.I quiet
Do not abort mounting when certain consistency checks fail.
.SH "Mount options for iso9660"
+ISO 9660 is a standard describing a filesystem structure to be used
+on CD-ROMs. (This filesystem type is also seen on some DVDs. See also the
+.I udf
+filesystem.)
+
Normal
.I iso9660
filenames appear in a 8.3 format (i.e., DOS-like restrictions on filename
Disable the use of Rock Ridge extensions, even if available. Cf.\&
.BR map .
.TP
+.B nojoliet
+Disable the use of Microsoft Joliet extensions, even if available. Cf.\&
+.BR map .
+.TP
.BR check=r[elaxed] " / " check=s[trict]
With
.BR check=relaxed ,
(Default:
.BR uid=0,gid=0 .)
.TP
-.BR map=n[ormal] " / " map=o[ff]
+.BR map=n[ormal] " / " map=o[ff] " / " map=a[corn]
For non-Rock Ridge volumes, normal name translation maps upper
to lower case ASCII, drops a trailing `;1', and converts `;' to `.'.
With
.BR norock .
(Default:
.BR map=normal .)
+.B map=acorn
+is like
+.BR map=normal
+but also apply Acorn extensions if present.
.TP
.BI mode= value
For non-Rock Ridge volumes, give all files the indicated mode.
.TP
.B unhide
Also show hidden and associated files.
+(If the ordinary files and the associated or hidden files have
+the same filenames, this may make the ordinary files inaccessible.)
.TP
.B block=[512|1024|2048]
Set the block size to the indicated value.
.BR conv=binary .)
Since Linux 1.3.54 this option has no effect anymore.
(And non-binary settings used to be very dangerous,
-often leading to silent data corruption.)
+possibly leading to silent data corruption.)
.TP
.B cruft
If the high byte of the file length contains other garbage,
The `cruft' option is set automatically if the entire CDROM
has a weird size (negative, or more than 800MB). It is also
set when volume sequence numbers other than 0 or 1 are seen.
+.TP
+.BI session= x
+Select number of session on multisession CD. (Since 2.3.4.)
+.TP
+.BI sbsector= xxx
+Session begins from sector xxx. (Since 2.3.4.)
+.LP
+The following options are the same as for vfat and specifying them only makes
+sense when using discs encoded using Microsoft's Joliet extensions.
+.TP
+.BI iocharset= value
+Character set to use for converting 16 bit Unicode characters on CD
+to 8 bit characters. The default is iso8859-1.
+.TP
+.B utf8
+Convert 16 bit Unicode characters on CD to UTF-8.
.SH "Mount options for minix"
None.
system read-only. The file system can be made writeable again by remounting
it.
-.SH "Mount options for ncp"
+.SH "Mount options for ncpfs"
Just like
-.IR nfs ", the " ncp
+.IR nfs ", the " ncpfs
implementation expects a binary argument (a
.IR "struct ncp_mount_data" )
to the mount system call. This argument is constructed by
.BR ncpmount (8)
and the current version of
.B mount
-(2.6h) does not know anything about ncp.
+(2.12) does not know anything about ncpfs.
.SH "Mount options for nfs"
Instead of a textual option string, parsed by the kernel, the
Especially useful options include
.TP
.B rsize=8192,wsize=8192
-This will make your nfs connection much faster than with the default
-buffer size of 1024.
+This will make your nfs connection faster than with the default
+buffer size of 4096. (NFSv2 does not work with larger values of
+.B rsize
+and
+.BR wsize .)
.TP
.B hard
The program accessing a file on a NFS mounted file system will hang
.B nolock
Do not use locking. Do not start lockd.
+.SH "Mount options for ntfs"
+.TP
+.BI iocharset= name
+Character set to use when returning file names.
+Unlike VFAT, NTFS suppresses names that contain
+unconvertible characters.
+.TP
+.BR utf8
+Use UTF-8 for converting file names.
+.TP
+.B uni_xlate=[0|1|2]
+For 0 (or `no' or `false'), do not use escape sequences
+for unknown Unicode characters.
+For 1 (or `yes' or `true') or 2, use vfat-style 4-byte escape sequences
+starting with ":". Here 2 give a little-endian encoding
+and 1 a byteswapped bigendian encoding.
+.TP
+.B posix=[0|1]
+If enabled (posix=1), the file system distinguishes between
+upper and lower case. The 8.3 alias names are presented as
+hard links instead of being suppressed.
+.TP
+\fBuid=\fP\fIvalue\fP, \fBgid=\fP\fIvalue\fP and \fBumask=\fP\fIvalue\fP
+Set the file permission on the filesystem.
+The umask value is given in octal.
+By default, the files are owned by root and not readable by somebody else.
+
.SH "Mount options for proc"
.TP
\fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
These options are recognized, but have no effect as far as I can see.
+.SH "Mount options for ramfs"
+Ramfs is a memory based filesystem. Mount it and you have it. Unmount it
+and it is gone. Present since Linux 2.3.99pre4.
+There are no mount options.
+
+.SH "Mount options for reiserfs"
+Reiserfs is a journaling filesystem.
+The reiserfs mount options are more fully described at
+.IR http://www.namesys.com/mount-options.html .
+.TP
+.BR conv
+Instructs version 3.6 reiserfs software to mount a version 3.5 file system,
+using the 3.6 format for newly created objects. This file system will no
+longer be compatible with reiserfs 3.5 tools.
+.TP
+.BR hash=rupasov " / " hash=tea " / " hash=r5 " / " hash=detect
+Choose which hash function reiserfs will use to find files within directories.
+.RS
+.TP
+.B rupasov
+A hash invented by Yury Yu. Rupasov. It is fast and preserves locality,
+mapping lexicographically close file names to close hash values.
+This option should not be used, as it causes a high probability of hash
+collisions.
+.TP
+.B tea
+A Davis-Meyer function implemented by Jeremy Fitzhardinge.
+It uses hash permuting bits in the name. It gets high randomness
+and, therefore, low probability of hash collisions at come CPU cost.
+This may be used if EHASHCOLLISION errors are experienced with the r5 hash.
+.TP
+.B r5
+A modified version of the rupasov hash. It is used by default and is
+the best choice unless the file system has huge directories and
+unusual file-name patterns.
+.TP
+.B detect
+Instructs
+.IR mount
+to detect which hash function is in use by examining
+the file system being mounted, and to write this information into
+the reiserfs superblock. This is only useful on the first mount of
+an old format file system.
+.RE
+.TP
+.BR hashed_relocation
+Tunes the block allocator. This may provide performance improvements
+in some situations.
+.TP
+.BR no_unhashed_relocation
+Tunes the block allocator. This may provide performance improvements
+in some situations.
+.TP
+.BR noborder
+Disable the border allocator algorithm invented by Yury Yu. Rupasov.
+This may provide performance improvements in some situations.
+.TP
+.BR nolog
+Disable journalling. This will provide slight performance improvements in
+some situations at the cost of losing reiserfs's fast recovery from crashes.
+Even with this option turned on, reiserfs still performs all journalling
+operations, save for actual writes into its journalling area. Implementation
+of
+.IR nolog
+is a work in progress.
+.TP
+.BR notail
+By default, reiserfs stores small files and `file tails' directly into its
+tree. This confuses some utilities such as
+.BR LILO (8) .
+This option is used to disable packing of files into the tree.
+.TP
+.BR replayonly
+Replay the transactions which are in the journal, but do not actually
+mount the file system. Mainly used by
+.IR reiserfsck .
+.TP
+.BI resize= number
+A remount option which permits online expansion of reiserfs partitions.
+Instructs reiserfs to assume that the device has
+.I number
+blocks.
+This option is designed for use with devices which are under logical
+volume management (LVM).
+There is a special
+.I resizer
+utility which can be obtained from
+.IR ftp://ftp.namesys.com/pub/reiserfsprogs .
+
.SH "Mount options for romfs"
None.
.SH "Mount options for smbfs"
Just like
-.IR nfs ", the " smb
+.IR nfs ", the " smbfs
implementation expects a binary argument (a
.IR "struct smb_mount_data" )
to the mount system call. This argument is constructed by
.BR smbmount (8)
and the current version of
.B mount
-(2.6c) does not know anything about smb.
+(2.12) does not know anything about smbfs.
.SH "Mount options for sysv"
None.
+.SH "Mount options for tmpfs"
+The following parameters accept a suffix
+.BR k ,
+.B m
+or
+.B g
+for Ki, Mi, Gi (binary kilo, mega and giga) and can be changed on remount.
+.TP
+.BI size= nbytes
+Override default size of the filesystem.
+The size is given in bytes, and rounded down to entire pages.
+The default is half of the memory.
+.TP
+.B nr_blocks=
+Set number of blocks.
+.TP
+.B nr_inodes=
+Set number of inodes.
+.TP
+.B mode=
+Set initial permissions of the root directory.
+
+.SH "Mount options for udf"
+udf is the "Universal Disk Format" filesystem defined by the Optical
+Storage Technology Association, and is often used for DVD-ROM.
+See also
+.IR iso9660 .
+.TP
+.B gid=
+Set the default group.
+.TP
+.B umask=
+Set the default umask.
+The value is given in octal.
+.TP
+.B uid=
+Set the default user.
+.TP
+.B unhide
+Show otherwise hidden files.
+.TP
+.B undelete
+Show deleted files in lists.
+.TP
+.B strict
+Set strict conformance (unused).
+.TP
+.B utf8
+(unused).
+.TP
+.B iocharset
+(unused).
+.TP
+.B bs=
+Set the block size. (May not work unless 2048.)
+.TP
+.B novrs
+Skip volume sequence recognition.
+.TP
+.B session=
+Set the CDROM session counting from 0. Default: last session.
+.TP
+.B anchor=
+Override standard anchor location. Default: 256.
+.TP
+.B volume=
+Override the VolumeDesc location. (unused)
+.TP
+.B partition=
+Override the PartitionDesc location. (unused)
+.TP
+.B lastblock=
+Set the last block of the filesystem.
+.TP
+.B fileset=
+Override the fileset block location. (unused)
+.TP
+.B rootdir=
+Override the root directory location. (unused)
+
.SH "Mount options for ufs"
-None.
+.TP
+.BI ufstype= value
+UFS is a file system widely used in different operating systems.
+The problem are differences among implementations. Features of some
+implementations are undocumented, so its hard to recognize the
+type of ufs automatically.
+That's why the user must specify the type of ufs by mount option.
+Possible values are:
+.RS
+.TP
+.B old
+Old format of ufs, this is the default, read only.
+(Don't forget to give the \-r option.)
+.TP
+.B 44bsd
+For filesystems created by a BSD-like system (NetBSD,FreeBSD,OpenBSD).
+.TP
+.B sun
+For filesystems created by SunOS or Solaris on Sparc.
+.TP
+.B sunx86
+For filesystems created by Solaris on x86.
+.TP
+.B nextstep
+For filesystems created by NeXTStep (on NeXT station) (currently read only).
+.TP
+.B nextstep-cd
+For NextStep CDROMs (block_size == 2048), read-only.
+.TP
+.B openstep
+For filesystems created by OpenStep (currently read only).
+The same filesystem type is also used by Mac OS X.
+.RE
+
+.TP
+.BI onerror= value
+Set behaviour on error:
+.RS
+.TP
+.B panic
+If an error is encountered, cause a kernel panic.
+.TP
+.B [lock|umount|repair]
+These mount options don't do anything at present;
+when an error is encountered only a console message is printed.
+.RE
.SH "Mount options for umsdos"
See mount options for msdos.
First try to make a short name without sequence number,
before trying
.IR name~num.ext .
+.TP
+.B utf8
+UTF8 is the filesystem safe 8-bit encoding of Unicode that is used
+by the console. It can be be enabled for the filesystem with this option.
+If `uni_xlate' gets set, UTF8 gets disabled.
+.TP
+.B shortname=[lower|win95|winnt|mixed]
+
+Defines the behaviour for creation and display of filenames which fit into
+8.3 characters. If a long name for a file exists, it will always be
+preferred display. There are four modes:
+.RS
+.TP
+.I lower
+Force the short name to lower case upon display; store a long name when
+the short name is not all upper case.
+.TP
+.I win95
+Force the short name to upper case upon display; store a long name when
+the short name is not all upper case.
+. TP
+.I winnt
+Display the shortname as is; store a long name when the short name is
+not all lower case or all upper case.
+.TP
+.I mixed
+Display the short name as is; store a long name when the short name is not
+all upper case.
+.RE
+
+The default is "lower".
.SH "Mount options for xenix"
None.
+.SH "Mount options for xfs"
+.TP
+.BI biosize= size
+Sets the preferred buffered I/O size (default size is 64K).
+.I 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
+.IR size .
+The preferred buffered I/O size can also be altered on an individual
+file basis using the
+.BR ioctl (2)
+system call.
+.TP
+.B dmapi " / " xdsm
+Enable the DMAPI (Data Management API) event callouts.
+.TP
+.BI 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,
+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.
+.TP
+.BI logbsize= value
+Set the size of each in-memory log buffer.
+Valid sizes are 16384 (16K) and 32768 (32K).
+The default value for machines with more than 32MB of memory is 32768,
+machines with less memory use 16384 by default.
+.TP
+\fBlogdev=\fP\fIdevice\fP and \fBrtdev=\fP\fIdevice\fP
+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.
+Refer to
+.BR xfs (5).
+.TP
+.B noalign
+Data allocations will not be aligned at stripe unit boundaries.
+.TP
+.B noatime
+Access timestamps are not updated when a file is read.
+.TP
+.B 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
+.B norecovery
+mode.
+Some files or directories may not be accessible because of this.
+Filesystems mounted
+.B norecovery
+must be mounted read-only or the mount will fail.
+.TP
+.B osyncisdsync
+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 in effect, timestamp updates from
+O_SYNC writes can be lost if the system crashes.
+.TP
+.BR quota " / " usrquota " / " uqnoenforce
+User disk quota accounting enabled, and limits (optionally) enforced.
+.TP
+.BR grpquota " / " gqnoenforce
+Group disk quota accounting enabled and limits (optionally) enforced.
+.TP
+\fBsunit=\fP\fIvalue\fP and \fBswidth=\fP\fIvalue\fP
+Used to specify the stripe unit and width for a RAID device or a stripe
+volume.
+.I 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
+.B swidth
+option is required if the
+.B sunit
+option has been specified,
+and must be a multiple of the
+.B sunit
+value.
+
.SH "Mount options for xiafs"
None. Although nothing is wrong with xiafs, it is not used much,
and is not maintained. Probably one shouldn't use it.
(but just an option `\fB\-o loop\fP' is given), then
.B mount
will try to find some unused loop device and use that.
+If you are not so unwise as to make
+.I /etc/mtab
+a symbolic link to
+.I /proc/mounts
+then any loop device allocated by
+.B mount
+will be freed by
+.BR umount .
+You can also free a loop device by hand, using `losetup -d', see
+.BR losetup (8).
+
+.SH RETURN CODES
+.B mount
+has the following return codes (the bits can be ORed):
+.TP
+.BR 0
+success
+.TP
+.BR 1
+incorrect invocation or permissions
+.TP
+.BR 2
+system error (out of memory, cannot fork, no more loop devices)
+.TP
+.BR 4
+internal
+.B mount
+bug or missing
+.BR nfs
+support in
+.B mount
+.TP
+.BR 8
+user interrupt
+.TP
+.BR 16
+problems writing or locking /etc/mtab
+.TP
+.BR 32
+mount failure
+.TP
+.BR 64
+some mount succeeded
.SH FILES
.I /etc/fstab
.BR umount (8),
.BR swapon (8),
.BR nfs (5),
+.BR xfs (5),
+.BR e2label (8),
+.BR xfs_admin (8),
.BR mountd (8),
.BR nfsd (8),
.BR mke2fs (8),
It is possible for a corrupted file system to cause a crash.
.PP
Some Linux file systems don't support
-.B "\-o sync"
-(the ext2fs
-.I does
+.B "\-o sync and \-o dirsync"
+(the ext2 and ext3 file systems
+.I do
support synchronous updates (a la BSD) when mounted with the
.B sync
option).
.SH HISTORY
A
.B mount
-command appeared in Version 6 AT&T UNIX.
+command existed in Version 5 AT&T UNIX.
projects / thirdparty / util-linux.git / blobdiff