1 .\" Copyright (c) 1996 Andries Brouwer
3 .\" This page is somewhat derived from a page that was
4 .\" (c) 1980, 1989, 1991 The Regents of the University of California
5 .\" and had been heavily modified by Rik Faith and myself.
6 .\" (Probably no BSD text remains.)
7 .\" Fragments of text were written by Werner Almesberger, Remy Card,
8 .\" Stephen Tweedie and Eric Youngdale.
10 .\" This is free documentation; you can redistribute it and/or
11 .\" modify it under the terms of the GNU General Public License as
12 .\" published by the Free Software Foundation; either version 2 of
13 .\" the License, or (at your option) any later version.
15 .\" The GNU General Public License's references to "object code"
16 .\" and "executables" are to be interpreted as the output of any
17 .\" document formatting or typesetting system, including
18 .\" intermediate and printed output.
20 .\" This manual is distributed in the hope that it will be useful,
21 .\" but WITHOUT ANY WARRANTY; without even the implied warranty of
22 .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 .\" GNU General Public License for more details.
25 .\" You should have received a copy of the GNU General Public
26 .\" License along with this manual; if not, write to the Free
27 .\" Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
30 .\" 960705, aeb: version for mount-2.7g
31 .\" 970114, aeb: xiafs and ext are dead; romfs is new
32 .\" 970623, aeb: -F option
33 .\" 970914, reg: -s option
34 .\" 981111, K.Garloff: /etc/filesystems
35 .\" 990111, aeb: documented /sbin/mount.smbfs
36 .\" 990730, Yann Droneaud <lch@multimania.com>: updated page
37 .\" 991214, Elrond <Elrond@Wunder-Nett.org>: added some docs on devpts
39 .TH MOUNT 8 "14 September 1997" "Linux 2.0" "Linux Programmer's Manual"
41 mount \- mount a file system
45 .BI "mount \-a [\-fFnrsvw] [\-t " vfstype ]
47 .BI "mount [\-fnrsvw] [\-o " options " [,...]] " "device " | " dir"
49 .BI "mount [\-fnrsvw] [\-t " vfstype "] [\-o " options "] " "device dir"
51 All files accessible in a Unix system are arranged in one big
52 tree, the file hierarchy, rooted at
54 These files can be spread out over several devices. The
56 command serves to attach the file system found on some device
57 to the big file tree. Conversely, the
59 command will detach it again.
61 The standard form of the
66 .BI "mount \-t" " type device dir"
68 This tells the kernel to attach the file system found on
74 The previous contents (if any) and owner and mode of
76 become invisible, and as long as this file system remains mounted,
79 refers to the root of the file system on
82 Three forms of invocation do not actually mount anything:
87 prints a help message;
92 prints a version string; and just
94 .BI "mount [-l] [-t" " type" ]
96 lists all mounted file systems (of type
98 The option \-l adds the (ext2) labels in this listing.
101 .\" In fact since 2.3.99. At first the syntax was mount -t bind.
102 Since Linux 2.4.0 it is possible to remount part of the
103 file hierarchy somewhere else. The call is
106 .B "mount --bind olddir newdir"
111 file system is not associated with a special device, and when
112 mounting it, an arbitrary keyword, such as
114 can be used instead of a device specification.
115 (The customary choice
117 is less fortunate: the error message `none busy' from
121 Most devices are indicated by a file name (of a block special device), like
123 but there are other possibilities. For example, in the case of an NFS mount,
126 .IR knuth.cwi.nl:/dir .
127 It is possible to indicate a block special device using its
128 volume label or UUID (see the \-L and \-U options below).
134 may contain lines describing what devices are usually
135 mounted where, using which options. This file is used in three ways:
140 .BI "mount \-a [-t" " type" ]
142 (usually given in a bootscript) causes all file systems mentioned in
144 (of the proper type) to be mounted as indicated, except for those
145 whose line contains the
149 option will make mount fork, so that the
150 filesystems are mounted simultaneously.
152 (ii) When mounting a file system mentioned in
154 it suffices to give only the device, or only the mount point.
156 (iii) Normally, only the superuser can mount file systems.
161 option on a line, then anybody can mount the corresponding system.
166 .B "/dev/cdrom /cd iso9660 ro,user,noauto,unhide"
168 any user can mount the iso9660 file system found on his CDROM
172 .B "mount /dev/cdrom"
179 For more details, see
181 Only the user that mounted a filesystem can unmount it again.
182 If any user should be able to unmount, then use
191 option is similar to the
193 option, with the restriction that the user must be the owner
194 of the special file. This may be useful e.g. for
196 if a login script makes the console user owner of this device.
202 maintain a list of currently mounted file systems in the file
204 If no arguments are given to
206 this list is printed.
209 filesystem is mounted (say at
215 have very similar contents. The former has somewhat
216 more information, such as the mount options used,
217 but is not necessarily up-to-date (cf. the
219 option below). It is possible to replace
221 by a symbolic link to
223 but some information is lost that way, and in particular
224 working with the loop device will be less convenient. Also,
225 pathnames containing spaces are handled correctly by
231 The full set of options used by an invocation of
233 is determined by first extracting the
234 options for the file system from the
236 table, then applying any options specified by the
238 argument, and finally applying a
240 option, when present.
242 Options available for the
250 Print a help message.
256 Mount all filesystems (of the given types) mentioned in
260 (Used in conjunction with
262 Fork off a new incarnation of mount for each device.
263 This will do the mounts on different devices or different NFS servers
265 This has the advantage that it is faster; also NFS timeouts go in
266 parallel. A disadvantage is that the mounts are done in undefined order.
267 Thus, you cannot use this option if you want to mount both
273 Causes everything to be done except for the actual system call; if it's not
274 obvious, this ``fakes'' mounting the file system. This option is useful in
277 flag to determine what the
279 command is trying to do. It can also be used to add entries for devices
280 that were mounted earlier with the -n option.
283 Add the ext2 labels in the mount output. Mount must have permission to
284 read the disk device (e.g. be suid root) for this to work.
285 One can set such a label
291 Mount without writing in
293 This is necessary for example when
295 is on a read-only file system.
298 Tolerate sloppy mount options rather than failing. This will ignore
299 mount options not supported by a filesystem type. Not all filesystems
300 support this option. This option exists for support of the Linux
301 autofs\-based automounter.
304 Mount the file system read-only. A synonym is
308 Mount the file system read/write. This is the default. A synonym is
312 Mount the partition that has the specified
316 Mount the partition that has the specified
318 These two options require the file
320 (present since Linux 2.1.116) to exist.
323 The argument following the
325 is used to indicate the file system type. The file system types which are
326 currently supported are listed in
327 .IR linux/fs/filesystems.c :
356 Note that coherent, sysv and xenix are equivalent and that
360 will be removed at some point in the future \(em use
362 instead. Since kernel version 2.1.21 the types
366 do not exist anymore.
368 For most types all the
370 program has to do is issue a simple
372 system call, and no detailed knowledge of the filesystem type is required.
373 For a few types however (like nfs, smbfs, ncpfs) ad hoc code is
374 necessary. The nfs ad hoc code is built in, but smbfs and ncpfs
375 have a separate mount program. In order to make it possible to
376 treat all types in a uniform way, mount will execute the program
378 (if that exists) when called with type
380 Since various versions of the
382 program have different calling conventions,
384 may have to be a shell script that sets up the desired call.
388 is the default. If no
390 option is given, or if the
392 type is specified, the superblock is probed for the filesystem type
393 .RI ( minix ", " ext ", " ext2 ", " xiafs ", " iso9660 ", " romfs
394 .RI , ufs ", " ntfs ", " qnx4 ", " bfs
396 If this probe fails, mount will try to read the file
397 .IR /etc/filesystems ,
398 or, if that does not exist,
399 .IR /proc/filesystems .
400 All of the filesystem types listed there will be tried,
401 except for those that are labeled "nodev" (e.g.,
409 type may be useful for user-mounted floppies.
412 can be useful to change the probe order (e.g., to try vfat before msdos)
413 or if you use a kernel module autoloader.
414 Warning: the probing uses a heuristic (the presence of appropriate `magic'),
415 and could recognize the wrong filesystem type.
417 More than one type may be specified in a comma separated
418 list. The list of file system types can be prefixed with
420 to specify the file system types on which no action should be taken.
421 (This can be meaningful with the
425 For example, the command:
428 .B "mount \-a \-t nomsdos,ext"
430 mounts all file systems except those of type
437 Options are specified with a
439 flag followed by a comma separated string of options.
440 Some of these options are only useful when they appear in the
442 file. The following options apply to any file system that is being
447 All I/O to the file system should be done asynchronously.
450 Update inode access time for each access. This is the default.
453 Can be mounted with the
459 .BR rw ", " suid ", " dev ", " exec ", " auto ", " nouser ", and " async.
462 Interpret character or block special devices on the file system.
465 Permit execution of binaries.
468 Do not update inode access times on this file system (e.g, for faster
469 access on the news spool to speed up news servers).
472 Can only be mounted explicitly (i.e., the
474 option will not cause the file system to be mounted).
477 Do not interpret character or block special devices on the file
481 Do not allow execution of any binaries on the mounted file system.
482 This option might be useful for a server that has file systems containing
483 binaries for architectures other than its own.
486 Do not allow set-user-identifier or set-group-identifier bits to take
487 effect. (This seems safe, but is in fact rather unsafe if you have
488 suidperl(1) installed.)
491 Forbid an ordinary (i.e., non-root) user to mount the file system.
495 Attempt to remount an already-mounted file system. This is commonly
496 used to change the mount flags for a file system, especially to make a
497 readonly file system writeable.
500 Mount the file system read-only.
503 Mount the file system read-write.
506 Allow set-user-identifier or set-group-identifier bits to take
510 All I/O to the file system should be done synchronously.
513 Allow an ordinary user to mount the file system. This option implies
515 .BR noexec ", " nosuid ", and " nodev
516 (unless overridden by subsequent options, as in the option line
517 .BR user,exec,dev,suid ).
520 .SH "FILESYSTEM SPECIFIC MOUNT OPTIONS"
521 The following options apply only to certain file systems.
522 We sort them by file system. They all follow the
526 .SH "Mount options for affs"
528 \fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
529 Set the owner and group of the root of the file system (default: uid=gid=0,
534 without specified value, the uid and gid of the current process are taken).
536 \fBsetuid=\fP\fIvalue\fP and \fBsetgid=\fP\fIvalue\fP
537 Set the owner and group of all files.
540 Set the mode of all files to
542 disregarding the original permissions.
543 Add search permission to directories that have read permission.
544 The value is given in octal.
547 Do not allow any changes to the protection bits on the file system.
550 Set uid and gid of the root of the file system to the uid and gid
551 of the mount point upon the first sync or umount, and then
552 clear this option. Strange...
555 Print an informational message for each successful mount.
558 Prefix used before volume name, when following a link.
561 Prefix (of length at most 30) used before '/' when following a symbolic link.
564 (Default: 2.) Number of unused blocks at the start of the device.
567 Give explicitly the location of the root block.
570 Give blocksize. Allowed values are 512, 1024, 2048, 4096.
572 .BR grpquota " / " noquota " / " quota " / " usrquota
573 These options are accepted but ignored.
575 .SH "Mount options for coherent"
578 .SH "Mount options for devpts"
579 The devpts file system is a pseudo file system, traditionally mounted on
581 In order to acquire a pseudo terminal, a process opens
583 the number of the pseudo terminal is then made available to the process
584 and the pseudo terminal slave can be accessed as
585 .IR /dev/pts/ <number>.
587 \fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
588 This sets the owner or the group of newly created PTYs to
589 the specified values. When nothing is specified, they will
590 be set to the UID and GID of the creating process.
591 For example, if there is a tty group with GID 5, then
593 will cause newly created PTYs to belong to the tty group.
596 Set the mode of newly created PTYs to the specified value.
602 makes "mesg y" the default on newly created PTYs.
604 .SH "Mount options for ext"
606 Note that the `ext' file system is obsolete. Don't use it.
607 Since Linux version 2.1.21 extfs is no longer part of the kernel source.
609 .SH "Mount options for ext2"
610 The `ext2' file system is the standard Linux file system.
611 Due to a kernel bug, it may be mounted with random mount options
612 (fixed in Linux 2.0.4).
614 .BR bsddf " / " minixdf
615 Set the behaviour for the
619 behaviour is to return in the
621 field the total number of blocks of the file system, while the
623 behaviour (which is the default) is to subtract the overhead blocks
624 used by the ext2 file system and not available for file storage. Thus
628 % mount /k -o minixdf; df /k; umount /k
629 Filesystem 1024-blocks Used Available Capacity Mounted on
630 /dev/sda6 2630655 86954 2412169 3% /k
631 % mount /k -o bsddf; df /k; umount /k
632 Filesystem 1024-blocks Used Available Capacity Mounted on
633 /dev/sda6 2543714 13 2412169 0% /k
636 (Note that this example shows that one can add command line options
637 to the options given in
641 .BR check " / " check=normal " / " check=strict
642 Set checking level. When at least one of these options is set (and
644 is set by default) the inodes and blocks bitmaps are checked upon mount
645 (which can take half a minute or so on a big disk, and is rather useless).
646 With strict checking, block deallocation checks that the block to free
649 .BR check=none " / " nocheck
650 No checking is done. This is fast. Recent kernels do not have a
651 check option anymore - checking with
656 Print debugging info upon each (re)mount.
658 .BR errors=continue " / " errors=remount-ro " / " errors=panic
659 Define the behaviour when an error is encountered.
660 (Either ignore errors and just mark the file system erroneous and continue,
661 or remount the file system read-only, or panic and halt the system.)
662 The default is set in the filesystem superblock, and can be
666 .BR grpid " or " bsdgroups " / " nogrpid " or " sysvgroups
667 These options define what group id a newly created file gets.
670 is set, it takes the group id of the directory in which it is created;
671 otherwise (the default) it takes the fsgid of the current process, unless
672 the directory has the setgid bit set, in which case it takes the gid
673 from the parent directory, and also gets the setgid bit set
674 if it is a directory itself.
676 \fBresgid=\fP\fIn\fP and \fBresuid=\fP\fIn\fP
677 The ext2 file system reserves a certain percentage of the available
678 space (by default 5%, see
682 These options determine who can use the reserved blocks.
683 (Roughly: whoever has the specified uid, or belongs to the specified group.)
686 Instead of block 1, use block
688 as superblock. This could be useful when the filesystem has been damaged.
689 (Earlier, copies of the superblock would be made every 8192 blocks: in
690 block 1, 8193, 16385, ... (and one got hundreds or even thousands
691 of copies on a big filesystem). Since version 1.08,
693 has a \-s (sparse superblock) option to reduce the number of backup
694 superblocks, and since version 1.15 this is the default. Note
695 that this may mean that ext2 filesystems created by a recent
697 cannot be mounted r/w under Linux 2.0.*.)
699 .BR grpquota " / " noquota " / " quota " / " usrquota
700 These options are accepted but ignored.
702 .SH "Mount options for fat"
705 is not a separate filesystem, but a common part of the
712 .BR blocksize=512 " / " blocksize=1024 " / " blocksize=2048
713 Set blocksize (default 512).
715 \fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
716 Set the owner and group of all files. (Default: the uid and gid
717 of the current process.)
720 Set the umask (the bitmask of the permissions that are
722 present). The default is the umask of the current process.
723 The value is given in octal.
726 Three different levels of pickyness can be chosen:
730 Upper and lower case are accepted and equivalent, long name parts are
732 .I verylongname.foobar
735 leading and embedded spaces are accepted in each name part (name and extension).
738 Like "relaxed", but many special characters (*, ?, <, spaces, etc.) are
739 rejected. This is the default.
742 Like "normal", but names may not contain long parts and special characters
743 that are sometimes used on Linux, but are not accepted by MS-DOS are
744 rejected. (+, =, spaces, etc.)
748 Sets the codepage for converting to shortname characters on FAT
749 and VFAT filesystems. By default, codepage 437 is used.
751 .BR conv=b[inary] " / " conv=t[ext] " / " conv=a[uto]
754 file system can perform CRLF<-->NL (MS-DOS text format to UNIX text
755 format) conversion in the kernel. The following conversion modes are
760 no translation is performed. This is the default.
763 CRLF<-->NL translation is performed on all files.
766 CRLF<-->NL translation is performed on all files that don't have a
767 "well-known binary" extension. The list of known extensions can be found at
770 (as of 2.0, the list is: exe, com, bin, app, sys, drv, ovl, ovr, obj,
771 lib, dll, pif, arc, zip, lha, lzh, zoo, tar, z, arj, tz, taz, tzp, tpz,
772 gz, tgz, deb, gif, bmp, tif, gl, jpg, pcx, tfm, vf, gf, pk, pxl, dvi).
774 Programs that do computed lseeks won't like in-kernel text conversion.
775 Several people have had their data ruined by this translation. Beware!
777 For file systems mounted in binary mode, a conversion tool
778 (fromdos/todos) is available.
781 .BI cvf_format= module
782 Forces the driver to use the CVF (Compressed Volume File) module
784 instead of auto-detection. If the kernel supports kmod, the
785 cvf_format=xxx option also controls on-demand CVF module loading.
787 .BI cvf_option= option
788 Option passed to the CVF module.
793 flag. A version string and a list of file system parameters will be
794 printed (these data are also printed if the parameters appear to be
797 .BR fat=12 " / " fat=16 " / " fat=32
798 Specify a 12, 16 or 32 bit fat. This overrides
799 the automatic FAT type detection routine. Use with caution!
802 Character set to use for converting between 8 bit characters
803 and 16 bit Unicode characters. The default is iso8859-1.
804 Long filenames are stored on disk in Unicode format.
809 flag. Attempts to chown or chmod files do not return errors,
810 although they fail. Use with caution!
812 .B "sys_immutable, showexec, dots, nodots, dotsOK=[yes|no]"
813 Various misguided attempts to force Unix or DOS conventions
814 onto a FAT file system.
816 .SH "Mount options for hpfs"
818 \fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
819 Set the owner and group of all files. (Default: the uid and gid
820 of the current process.)
823 Set the umask (the bitmask of the permissions that are
825 present). The default is the umask of the current process.
826 The value is given in octal.
828 .BR case=lower " / " case=asis
829 Convert all files names to lower case, or leave them.
833 .BR conv=binary " / " conv=text " / " conv=auto
836 delete some random CRs (in particular, all followed by NL)
840 choose more or less at random between
841 .BR conv=binary " and " conv=text .
844 just read what is in the file. This is the default.
847 Do not abort mounting when certain consistency checks fail.
849 .SH "Mount options for iso9660"
852 filenames appear in a 8.3 format (i.e., DOS-like restrictions on filename
853 length), and in addition all characters are in upper case. Also there is
854 no field for file ownership, protection, number of links, provision for
855 block/character devices, etc.
857 Rock Ridge is an extension to iso9660 that provides all of these unix like
858 features. Basically there are extensions to each directory record that
859 supply all of the additional information, and when Rock Ridge is in use,
860 the filesystem is indistinguishable from a normal UNIX file system (except
861 that it is read-only, of course).
864 Disable the use of Rock Ridge extensions, even if available. Cf.\&
867 Disable the use of Microsoft Joliet extensions, even if available. Cf.\&
870 .BR check=r[elaxed] " / " check=s[trict]
873 a filename is first converted to lower case before doing the lookup.
874 This is probably only meaningful together with
881 \fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
882 Give all files in the file system the indicated user or group id,
883 possibly overriding the information found in the Rock Ridge extensions.
887 .BR map=n[ormal] " / " map=o[ff] " / " map=a[corn]
888 For non-Rock Ridge volumes, normal name translation maps upper
889 to lower case ASCII, drops a trailing `;1', and converts `;' to `.'.
892 no name translation is done. See
899 but also apply Acorn extensions if present.
902 For non-Rock Ridge volumes, give all files the indicated mode.
903 (Default: read permission for everybody.)
904 Since Linux 2.1.37 one no longer needs to specify the mode in
905 decimal. (Octal is indicated by a leading 0.)
908 Also show hidden and associated files.
910 .B block=[512|1024|2048]
911 Set the block size to the indicated value.
915 .BR conv=a[uto] " / " conv=b[inary] " / " conv=m[text] " / " conv=t[ext]
918 Since Linux 1.3.54 this option has no effect anymore.
919 (And non-binary settings used to be very dangerous,
920 possibly leading to silent data corruption.)
923 If the high byte of the file length contains other garbage,
924 set this mount option to ignore the high order bits of the file length.
925 This implies that a file cannot be larger than 16MB.
926 The `cruft' option is set automatically if the entire CDROM
927 has a weird size (negative, or more than 800MB). It is also
928 set when volume sequence numbers other than 0 or 1 are seen.
931 Select number of session on multisession CD. (Since 2.3.4.)
934 Session begins from sector xxx. (Since 2.3.4.)
936 .SH "Mount options for minix"
939 .SH "Mount options for msdos"
940 See mount options for fat.
943 file system detects an inconsistency, it reports an error and sets the file
944 system read-only. The file system can be made writeable again by remounting
947 .SH "Mount options for ncp"
950 implementation expects a binary argument (a
951 .IR "struct ncp_mount_data" )
952 to the mount system call. This argument is constructed by
954 and the current version of
956 (2.6h) does not know anything about ncp.
958 .SH "Mount options for nfs"
959 Instead of a textual option string, parsed by the kernel, the
961 file system expects a binary argument of type
962 .IR "struct nfs_mount_data" .
965 itself parses the following options of the form `tag=value',
966 and puts them in the structure mentioned:
987 is accepted but ignored.
988 Also the following Boolean options, possibly preceded by
1005 Especially useful options include
1007 .B rsize=8192,wsize=8192
1008 This will make your nfs connection much faster than with the default
1009 buffer size of 1024. (NFSv2 does not work with larger values of
1015 The program accessing a file on a NFS mounted file system will hang
1016 when the server crashes. The process cannot be interrupted or
1017 killed unless you also specify
1019 When the NFS server is back online the program will continue undisturbed
1020 from where it was. This is probably what you want.
1023 This option allows the kernel to time out if the nfs server is not
1024 responding for some time. The time can be
1027 This option might be useful if your nfs server sometimes doesn't respond
1028 or will be rebooted while some process tries to get a file from the server.
1029 Usually it just causes lots of trouble.
1032 Do not use locking. Do not start lockd.
1034 .SH "Mount options for ntfs"
1037 Character set to use when returning file names.
1038 Unlike VFAT, NTFS suppresses names that contain
1039 unconvertible characters.
1042 Use UTF-8 for converting file names.
1044 .B uni_xlate=[0|1|2]
1045 For 0 (or `no' or `false') or 1 (or `yes' or `true'):
1046 use the VFAT-style encoding for file names outside the current
1047 character set. A value of 2 will disable the encoding with ":".
1050 If enabled (posix=1), the file system distinguishes between
1051 upper and lower case. The 8.3 alias names are presented as
1052 hard links instead of being suppressed.
1054 \fBuid=\fP\fIvalue\fP, \fBgid=\fP\fIvalue\fP and \fBumask=\fP\fIvalue\fP
1055 Set the file permission on the filesystem.
1056 By default, the files are owned by root and not readable by somebody else.
1058 .SH "Mount options for proc"
1060 \fBuid=\fP\fIvalue\fP and \fBgid=\fP\fIvalue\fP
1061 These options are recognized, but have no effect as far as I can see.
1063 .SH "Mount options for romfs"
1066 .SH "Mount options for smbfs"
1068 .IR nfs ", the " smb
1069 implementation expects a binary argument (a
1070 .IR "struct smb_mount_data" )
1071 to the mount system call. This argument is constructed by
1073 and the current version of
1075 (2.9w) does not know anything about smb.
1077 .SH "Mount options for sysv"
1080 .SH "Mount options for udf"
1083 Set the default group.
1086 Set the default umask.
1089 Set the default user.
1092 Show otherwise hidden files.
1095 Show deleted files in lists.
1098 Set strict conformance (unused).
1107 Set the block size. (May not work unless 2048.)
1110 Skip volume sequence recognition.
1113 Set the CDROM session counting from 0. Default: last session.
1116 Override standard anchor location. Default: 256.
1119 Override the VolumeDesc location. (unused)
1122 Override the PartitionDesc location. (unused)
1125 Set the last block of the filesystem.
1128 Override the fileset block location. (unused)
1131 Override the root directory location. (unused)
1133 .SH "Mount options for ufs"
1136 UFS is a file system widely used in different operating systems.
1137 The problem are differences among implementations. Features of some
1138 implementations are undocumented, so its hard to recognize the
1139 type of ufs automatically.
1140 That's why user must specify the type of ufs by mount option.
1141 Possible values are:
1145 Old format of ufs, this is the default, read only.
1148 For filesystems created by a BSD-like system (NetBSD,FreeBSD,OpenBSD).
1151 For filesystems created by SunOS or Solaris on Sparc.
1154 For filesystems created by Solaris on x86.
1157 For filesystems created by NeXTStep (on NeXT station) (currently read only).
1160 For NextStep CDROMs (block_size == 2048), read-only.
1163 For filesystems created by OpenStep (currently read only).
1168 Set behaviour on error:
1172 If an error is encountered, cause a kernel panic.
1174 .B [lock|umount|repair]
1175 These mount options don't do anything at present;
1176 when an error is encountered only a console message is printed.
1179 .SH "Mount options for umsdos"
1180 See mount options for msdos.
1183 option is explicitly killed by
1186 .SH "Mount options for vfat"
1187 First of all, the mount options for
1192 option is explicitly killed by
1194 Furthermore, there are
1197 Translate unhandled Unicode characters to special escaped sequences.
1198 This lets you backup and restore filenames that are created with any
1199 Unicode characters. Without this option, a '?' is used when no
1200 translation is possible. The escape character is ':' because it is
1201 otherwise illegal on the vfat filesystem. The escape sequence
1202 that gets used, where u is the unicode character,
1203 is: ':', (u & 0x3f), ((u>>6) & 0x3f), (u>>12).
1206 Allow two files with names that only differ in case.
1209 First try to make a short name without sequence number,
1214 UTF8 is the filesystem safe 8-bit encoding of Unicode that is used
1215 by the console. It can be be enabled for the filesystem with this option.
1216 If `uni_xlate' gets set, UTF8 gets disabled.
1218 .SH "Mount options for xenix"
1221 .SH "Mount options for xiafs"
1222 None. Although nothing is wrong with xiafs, it is not used much,
1223 and is not maintained. Probably one shouldn't use it.
1224 Since Linux version 2.1.21 xiafs is no longer part of the kernel source.
1226 .SH "THE LOOP DEVICE"
1227 One further possible type is a mount via the loop device. For example,
1231 .B " mount /tmp/fdimage /mnt -t msdos -o loop=/dev/loop3,blocksize=1024"
1234 will set up the loop device
1236 to correspond to the file
1238 and then mount this device on
1240 This type of mount knows about three options, namely
1241 .BR loop ", " offset " and " encryption ,
1242 that are really options to
1244 If no explicit loop device is mentioned
1245 (but just an option `\fB\-o loop\fP' is given), then
1247 will try to find some unused loop device and use that.
1248 If you are not so unwise as to make
1252 then any loop device allocated by
1256 You can also free a loop device by hand, using `losetup -d', see
1264 table of mounted file systems
1285 It is possible for a corrupted file system to cause a crash.
1287 Some Linux file systems don't support
1291 support synchronous updates (a la BSD) when mounted with the
1297 may not be able to change mount parameters (all
1298 .IR ext2fs -specific
1301 are changeable with a remount, for example, but you can't change
1310 command existed in Version 5 AT&T UNIX.
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