mount



MOUNT(8)                   Linux Programmer’s Manual                  MOUNT(8)




NAME

       mount - mount a file system


SYNOPSIS

       mount [-lhV]

       mount -a [-fFnrsvw] [-t vfstype] [-O optlist]
       mount [-fnrsvw] [-o options [,...]] device | dir
       mount [-fnrsvw] [-t vfstype] [-o options] device dir


DESCRIPTION

       All files accessible in a Unix system are arranged in one big tree, the
       file hierarchy, rooted at /.  These files can be spread out  over  sev-
       eral  devices. The mount command serves to attach the file system found
       on some device to the big file tree. Conversely, the umount(8)  command
       will detach it again.

       The standard form of the mount command, is
              mount -t type device dir
       This  tells the kernel to attach the file system found on device (which
       is of type type) at the directory dir.  The previous contents (if  any)
       and  owner  and  mode of dir become invisible, and as long as this file
       system remains mounted, the pathname dir refers to the root of the file
       system on device.

       Three forms of invocation do not actually mount anything:
              mount -h
       prints a help message;
              mount -V
       prints a version string; and just
              mount [-l] [-t type]
       lists  all mounted file systems (of type type).  The option -l adds the
       (ext2, ext3 and XFS) labels in this listing.  See below.

       Since Linux 2.4.0 it is possible to remount part of the file  hierarchy
       somewhere else. The call is
              mount --bind olddir newdir
       After this call the same contents is accessible in two places.  One can
       also remount a single file (on a single file).

       This call attaches only (part of) a  single  filesystem,  not  possible
       submounts.  The entire file hierarchy including submounts is attached a
       second place using
              mount --rbind olddir newdir

       Note that the filesystem mount options will remain the same as those on
       the  original  mount  point,  and  cannot  be changed by passing the -o
       option along with --bind/--rbind.

       Since Linux 2.5.1 it is possible to atomically move a mounted  tree  to
       another place. The call is
              mount --move olddir newdir

       The  proc file system is not associated with a special device, and when
       mounting it, an arbitrary keyword, such as proc can be used instead  of
       a  device specification.  (The customary choice none is less fortunate:
       the error message ‘none busy’ from umount can be confusing.)

       Most devices are indicated by a file name (of a block special  device),
       like  /dev/sda1, but there are other possibilities. For example, in the
       case of an NFS mount, device may look like  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 /etc/fstab (see fstab(5)), may contain lines  describing  what
       devices  are  usually  mounted where, using which options. This file is
       used in three ways:

       (i) The command
              mount -a [-t type] [-O optlist]
       (usually given in a bootscript) causes all file  systems  mentioned  in
       fstab  (of  the  proper  type  and/or  having  or not having the proper
       options) to be mounted as indicated, except for those whose  line  con-
       tains the noauto keyword. Adding the -F option will make mount fork, so
       that the filesystems are mounted simultaneously.

       (ii) When mounting a file system mentioned in  fstab,  it  suffices  to
       give only the device, or only the mount point.

       (iii)  Normally,  only  the superuser can mount file systems.  However,
       when fstab contains the user option on a line, anybody  can  mount  the
       corresponding system.

       Thus, given a line
              /dev/cdrom  /cd  iso9660  ro,user,noauto,unhide
       any user can mount the iso9660 file system found on his CDROM using the
       command
              mount /dev/cdrom
       or
              mount /cd
       For more details, see fstab(5).  Only the user that mounted a  filesys-
       tem  can unmount it again.  If any user should be able to unmount, then
       use users instead of user in the fstab line.  The owner option is simi-
       lar  to the user option, with the restriction that the user must be the
       owner of the special file. This may be useful e.g.  for  /dev/fd  if  a
       login  script  makes  the console user owner of this device.  The group
       option is similar, with the restriction that the user must be member of
       the group of the special file.

       The programs mount and umount maintain a list of currently mounted file
       systems in the file /etc/mtab.  If no arguments  are  given  to  mount,
       this list is printed.

       When the proc filesystem is mounted (say at /proc), the files /etc/mtab
       and /proc/mounts have very similar contents. The  former  has  somewhat
       more  information, such as the mount options used, but is not necessar-
       ily up-to-date (cf. the -n option below). It  is  possible  to  replace
       /etc/mtab  by  a symbolic link to /proc/mounts, and especially when you
       have very large numbers of mounts things will be much faster with  that
       symlink, but some information is lost that way, and in particular work-
       ing with the loop device will be less convenient, and using the  "user"
       option will fail.



OPTIONS

       The full set of options used by an invocation of mount is determined by
       first extracting the options for the file system from the fstab  table,
       then  applying  any  options  specified by the -o argument, and finally
       applying a -r or -w option, when present.

       Options available for the mount command:

       -V     Output version.

       -h     Print a help message.

       -v     Verbose mode.

       -a     Mount all filesystems (of the given types) mentioned in fstab.

       -F     (Used in conjunction with -a.)  Fork off a  new  incarnation  of
              mount  for  each  device.   This will do the mounts on different
              devices or different NFS servers  in  parallel.   This  has  the
              advantage that it is faster; also NFS timeouts go in parallel. A
              disadvantage is that the mounts are  done  in  undefined  order.
              Thus,  you cannot use this option if you want to mount both /usr
              and /usr/spool.

       -f     Causes everything to be done except for the actual system  call;
              if  it’s  not  obvious, this ‘‘fakes’’ mounting the file system.
              This option is useful in conjunction with the -v flag to  deter-
              mine what the mount command is trying to do. It can also be used
              to add entries for devices that were mounted earlier with the -n
              option.

       -i     Don’t  call  the  /sbin/mount.<filesystem>  helper  even  if  it
              exists.

       -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 e2label(8) utility, or for XFS using xfs_admin(8), or
              for reiserfs using reiserfstune(8).

       -n     Mount without writing in /etc/mtab.  This is necessary for exam-
              ple when /etc is on a read-only file system.

       -p num In  case  of  a  loop mount with encryption, read the passphrase
              from file descriptor num instead of from the terminal.

       -s     Tolerate sloppy mount options rather  than  failing.  This  will
              ignore mount options not supported by a filesystem type. Not all
              filesystems support this option. This option exists for  support
              of the Linux autofs-based automounter.

       -r     Mount the file system read-only. A synonym is -o ro.

       -w     Mount the file system read/write. This is the default. A synonym
              is -o rw.

       -L label
              Mount the partition that has the specified label.

       -U uuid
              Mount the partition that has  the  specified  uuid.   These  two
              options  require  the file /proc/partitions (present since Linux
              2.1.116) to exist.

       -t vfstype
              The argument following the -t is used to indicate the file  sys-
              tem  type.   The file system types which are currently supported
              include: adfs, affs, autofs,  coda,  coherent,  cramfs,  devpts,
              efs,  ext,  ext2,  ext3,  hfs, hpfs, iso9660, jfs, minix, msdos,
              ncpfs, nfs, nfs4, ntfs,  proc,  qnx4,  ramfs,  reiserfs,  romfs,
              smbfs,  sysv,  tmpfs, udf, ufs, umsdos, usbfs, vfat, xenix, xfs,
              xiafs.  Note that coherent, sysv and xenix  are  equivalent  and
              that  xenix  and  coherent  will be removed at some point in the
              future — use sysv instead. Since kernel version 2.1.21 the types
              ext  and xiafs do not exist anymore. Earlier, usbfs was known as
              usbdevfs.

              For most types all the mount program has to do is issue a simple
              mount(2)  system call, and no detailed knowledge of the filesys-
              tem type is required.  For a few types however (like nfs,  nfs4,
              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 /sbin/mount.TYPE (if that exists)
              when  called with type TYPE.  Since various versions of the smb-
              mount    program    have    different    calling    conventions,
              /sbin/mount.smbfs may have to be a shell script that sets up the
              desired call.

              If no -t option is given, or if  the  auto  type  is  specified,
              mount will try to guess the desired type.  If mount was compiled
              with the blkid library, the guessing is done  by  this  library.
              Otherwise,  mount  guesses  itself by probing the superblock; if
              that does not turn up anything that looks familiar,  mount  will
              try  to  read  the  file  /etc/filesystems, or, if that does not
              exist, /proc/filesystems.  All of the  filesystem  types  listed
              there  will  be tried, except for those that are labeled "nodev"
              (e.g., devpts, proc, nfs, and nfs4).  If  /etc/filesystems  ends
              in  a  line with a single * only, mount will read /proc/filesys-
              tems afterwards.

              The auto type may be useful for user-mounted floppies.  Creating
              a  file /etc/filesystems can be useful to change the probe order
              (e.g., to try vfat before msdos or ext3 before ext2) or  if  you
              use  a  kernel  module  autoloader.  Warning: the probing uses a
              heuristic (the presence of appropriate ‘magic’), and could  rec-
              ognize  the  wrong  filesystem  type, possibly with catastrophic
              consequences. If your data  is  valuable,  don’t  ask  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 no to specify
              the file system types on which no action should be taken.  (This
              can be meaningful with the -a option.)

              For example, the command:
                     mount -a -t nomsdos,ext
              mounts all file systems except those of type msdos and ext.

       -O     Used in conjunction with -a, to limit the set of filesystems  to
              which  the -a is applied.  Like -t in this regard except that it
              is useless except in the context of -a.  For example,  the  com-
              mand:
                     mount -a -O no_netdev
              mounts all file systems except those which have the option _net-
              dev specified in the options field in the /etc/fstab file.

              It is different from -t in that each option is matched  exactly;
              a  leading no at the beginning of one option does not negate the
              rest.

              The -t and -O options are cumulative in  effect;  that  is,  the
              command
                     mount -a -t ext2 -O _netdev
              mounts  all  ext2  filesystems  with the _netdev option, not all
              filesystems that are either ext2  or  have  the  _netdev  option
              specified.

       -o     Options  are  specified with a -o flag followed by a comma sepa-
              rated string of options.  Some of these options are only  useful
              when  they appear in the /etc/fstab file.  The following options
              apply to any file system that is being mounted  (but  not  every
              file  system  actually honors them - e.g., the sync option today
              has effect only for ext2, ext3, fat, vfat and ufs):

              async  All I/O to the file system should be done asynchronously.

              atime  Update  inode  access  time  for each access. This is the
                     default.

              auto   Can be mounted with the -a option.

              defaults
                     Use default options: rw, suid, dev, exec,  auto,  nouser,
                     and async.

              dev    Interpret  character or block special devices on the file
                     system.

              exec   Permit execution of binaries.

              group  Allow an ordinary (i.e., non-root) user to mount the file
                     system  if  one  of  his  groups matches the group of the
                     device.  This option implies the options nosuid and nodev
                     (unless  overridden  by  subsequent  options,  as  in the
                     option line group,dev,suid).

              mand   Allow mandatory locks on this filesystem. See fcntl(2).

              _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).

              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).

              noauto Can  only be mounted explicitly (i.e., the -a option will
                     not cause the file system to be mounted).

              nodev  Do not interpret character or block  special  devices  on
                     the file system.

              noexec Do  not  allow  direct  execution  of any binaries on the
                     mounted file system.  (Until recently it was possible  to
                     run  binaries  anyway  using  a  command like /lib/ld*.so
                     /mnt/binary.  This  trick  fails  since  Linux  2.4.25  /
                     2.6.0.)

              nomand Do not allow mandatory locks on this filesystem.

              nosuid Do  not allow set-user-identifier or set-group-identifier
                     bits to take effect. (This seems safe,  but  is  in  fact
                     rather unsafe if you have suidperl(1) installed.)

              nouser Forbid  an  ordinary  (i.e.,  non-root) user to mount the
                     file system.  This is the default.

              owner  Allow an ordinary (i.e., non-root) user to mount the file
                     system  if  he  is  the owner of the device.  This option
                     implies the options nosuid and nodev  (unless  overridden
                     by   subsequent   options,   as   in   the   option  line
                     owner,dev,suid).

              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  write-
                     able. It does not change device or mount point.

              ro     Mount the file system read-only.

              rw     Mount the file system read-write.

              suid   Allow set-user-identifier or set-group-identifier bits to
                     take effect.

              sync   All I/O to the file system should be done  synchronously.
                     In  case  of  media  with  limited number of write cycles
                     (e.g. some flash  drives)  "sync"  may  cause  life-cycle
                     shortening.

              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.

              user   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 noexec, nosuid, and nodev (unless overridden
                     by  subsequent   options,   as   in   the   option   line
                     user,exec,dev,suid).

              users  Allow  every  user  to mount and unmount the file system.
                     This option implies the options noexec, nosuid, and nodev
                     (unless  overridden  by  subsequent  options,  as  in the
                     option line users,exec,dev,suid).

       --bind Remount a subtree somewhere  else  (so  that  its  contents  are
              available in both places). See above.

       --move Move a subtree to some other place. See above.



FILESYSTEM SPECIFIC MOUNT OPTIONS

       The following options apply only to certain file systems.  We sort them
       by file system. They all follow the -o flag.

       What options are supported depends a bit on the running  kernel.   More
       info  may  be  found  in  the  kernel  source  subdirectory  Documenta-
       tion/filesystems.



Mount options for adfs

       uid=value and gid=value
              Set the owner  and  group  of  the  files  in  the  file  system
              (default: uid=gid=0).

       ownmask=value and othmask=value
              Set the permission mask for ADFS ’owner’ permissions and ’other’
              permissions,  respectively  (default:  0700  and  0077,  respec-
              tively).     See    also   /usr/src/linux/Documentation/filesys-
              tems/adfs.txt.


Mount options for affs

       uid=value and gid=value
              Set the owner and group of the root of the file system (default:
              uid=gid=0,  but  with option uid or gid without specified value,
              the uid and gid of the current process are taken).

       setuid=value and setgid=value
              Set the owner and group of all files.

       mode=value
              Set the mode of all files to value & 0777 disregarding the orig-
              inal  permissions.   Add  search  permission to directories that
              have read permission.  The value is given in octal.

       protect
              Do not allow any changes to the protection bits on the file sys-
              tem.

       usemp  Set  uid  and  gid of the root of the file system to the uid and
              gid of the mount point upon the first sync or umount,  and  then
              clear this option. Strange...

       verbose
              Print an informational message for each successful mount.

       prefix=string
              Prefix used before volume name, when following a link.

       volume=string
              Prefix  (of  length at most 30) used before ’/’ when following a
              symbolic link.

       reserved=value
              (Default: 2.) Number of  unused  blocks  at  the  start  of  the
              device.

       root=value
              Give explicitly the location of the root block.

       bs=value
              Give blocksize. Allowed values are 512, 1024, 2048, 4096.

       grpquota / noquota / quota / usrquota
              These  options are accepted but ignored.  (However, quota utili-
              ties may react to such strings in /etc/fstab.)



Mount options for coherent

       None.



Mount options for devpts

       The devpts file system is a pseudo file system,  traditionally  mounted
       on  /dev/pts.   In  order to acquire a pseudo terminal, a process opens
       /dev/ptmx; the number of the pseudo terminal is then made available  to
       the   process  and  the  pseudo  terminal  slave  can  be  accessed  as
       /dev/pts/<number>.

       uid=value and gid=value
              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 gid=5 will cause newly created
              PTYs to belong to the tty group.

       mode=value
              Set the mode of newly created PTYs to the specified value.   The
              default  is  0600.  A value of mode=620 and gid=5 makes "mesg y"
              the default on newly created PTYs.



Mount options for ext

       None.  Note that the ‘ext’ file  system  is  obsolete.  Don’t  use  it.
       Since  Linux  version  2.1.21  extfs  is  no  longer part of the kernel
       source.



Mount options for ext2

       The ‘ext2’ file system is the standard Linux file system.  Since  Linux
       2.5.46,  for  most  mount  options  the  default  is  determined by the
       filesystem superblock. Set them with tune2fs(8).

       acl / noacl
              Support POSIX Access Control Lists (or not).

       bsddf / minixdf
              Set the behaviour  for  the  statfs  system  call.  The  minixdf
              behaviour is to return in the f_blocks field the total number of
              blocks of the file system, while the bsddf behaviour  (which  is
              the default) is to subtract the overhead blocks used by the ext2
              file system and not available for file storage. Thus

       % mount /k -o minixdf; df /k; umount /k
       Filesystem   1024-blocks  Used Available Capacity Mounted on
       /dev/sda6      2630655   86954  2412169      3%   /k
       % mount /k -o bsddf; df /k; umount /k
       Filesystem   1024-blocks  Used Available Capacity Mounted on
       /dev/sda6      2543714      13  2412169      0%   /k

       (Note that this example shows that one can add command line options  to
       the options given in /etc/fstab.)


       check  Check filesystem (block and inode bitmaps) at mount time.

       check=none / nocheck
              No  checking is done at mount time. This is the default. This is
              fast.  It is wise to invoke e2fsck(8) every now and  then,  e.g.
              at boot time.

       debug  Print debugging info upon each (re)mount.

       errors=continue / errors=remount-ro / errors=panic
              Define  the  behaviour  when  an  error is encountered.  (Either
              ignore errors and just mark the file system erroneous  and  con-
              tinue,  or  remount the file system read-only, or panic and halt
              the system.)  The default is set in the  filesystem  superblock,
              and can be changed using tune2fs(8).

       grpid or bsdgroups / nogrpid or 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.

       grpquota / noquota / quota / usrquota
              These options are accepted but ignored.

       nobh   Do not attach buffer_heads to file pagecache. (Since 2.5.49.)

       nouid32
              Disables 32-bit UIDs and GIDs.   This  is  for  interoperability
              with older kernels which only store and expect 16-bit values.

       oldalloc or orlov
              Use  old  allocator  or Orlov allocator for new inodes. Orlov is
              default.

       resgid=n and resuid=n
              The ext2 file system reserves a certain percentage of the avail-
              able space (by default 5%, see mke2fs(8) and tune2fs(8)).  These
              options determine who can use the  reserved  blocks.   (Roughly:
              whoever  has  the  specified  uid,  or  belongs to the specified
              group.)

       sb=n   Instead of block 1, use block n as  superblock.  This  could  be
              useful  when  the filesystem has been damaged.  (Earlier, copies
              of the superblock would be made every 8192 blocks: in  block  1,
              8193,  16385,  ...  (and  one  got  thousands of copies on a big
              filesystem).  Since  version  1.08,  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 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".

       user_xattr / nouser_xattr
              Support "user." extended attributes (or not).




Mount options for ext3

       The ‘ext3’ file system is a 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:

       journal=update
              Update the ext3 file system’s journal to the current format.

       journal=inum
              When a journal already exists, this option  is  ignored.  Other-
              wise,  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 inum.

       noload Do not load the ext3 file system’s journal on mounting.

       data=journal / data=ordered / data=writeback
              Specifies the journalling  mode  for  file  data.   Metadata  is
              always  journaled.   To use modes other than ordered on the root
              file system, pass the mode to the kernel as boot parameter, e.g.
              rootflags=data=journal.

              journal
                     All  data  is  committed  into the journal prior to being
                     written into the main file system.

              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.

              writeback
                     Data ordering is not preserved - data may be written into
                     the  main file system after its metadata has been commit-
                     ted 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.

       commit=nrsec
              Sync  all  data  and  metadata  every nrsec seconds. The default
              value is 5 seconds. Zero means default.



Mount options for fat

       (Note: fat is not a separate filesystem,  but  a  common  part  of  the
       msdos, umsdos and vfat filesystems.)

       blocksize=512 / blocksize=1024 / blocksize=2048
              Set blocksize (default 512).

       uid=value and gid=value
              Set the owner and group of all files.  (Default: the uid and gid
              of the current process.)

       umask=value
              Set the umask (the bitmask  of  the  permissions  that  are  not
              present).  The default is the umask of the current process.  The
              value is given in octal.

       dmask=value
              Set the umask applied to directories only.  The default  is  the
              umask of the current process.  The value is given in octal.

       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.

       check=value
              Three different levels of pickyness can be chosen:

              r[elaxed]
                     Upper and lower case are accepted  and  equivalent,  long
                     name   parts  are  truncated  (e.g.   verylongname.foobar
                     becomes verylong.foo), leading and  embedded  spaces  are
                     accepted in each name part (name and extension).

              n[ormal]
                     Like  "relaxed",  but  many  special characters (*, ?, <,
                     spaces, etc.) are rejected.  This is the default.

              s[trict]
                     Like "normal", but names may not contain long  parts  and
                     special  characters that are sometimes used on Linux, but
                     are not accepted by MS-DOS are rejected. (+,  =,  spaces,
                     etc.)

       codepage=value
              Sets  the codepage for converting to shortname characters on FAT
              and VFAT filesystems. By default, codepage 437 is used.

       conv=b[inary] / conv=t[ext] / conv=a[uto]
              The fat file system can perform CRLF<-->NL (MS-DOS  text  format
              to  UNIX  text  format)  conversion in the kernel. The following
              conversion modes are available:

              binary no translation is performed.  This is the default.

              text   CRLF<-->NL translation is performed on all files.

              auto   CRLF<-->NL translation is performed  on  all  files  that
                     don’t  have  a "well-known binary" extension. The list of
                     known  extensions  can  be  found  at  the  beginning  of
                     fs/fat/misc.c  (as  of  2.0,  the list is: exe, com, bin,
                     app, sys, drv, ovl, ovr, obj, lib, dll,  pif,  arc,  zip,
                     lha,  lzh,  zoo, tar, z, arj, tz, taz, tzp, tpz, gz, tgz,
                     deb, gif, bmp, tif, gl, jpg, pcx, tfm, vf, gf,  pk,  pxl,
                     dvi).

              Programs  that do computed lseeks won’t like in-kernel text con-
              version.  Several people have had  their  data  ruined  by  this
              translation. Beware!

              For  file  systems  mounted  in  binary  mode, a conversion tool
              (fromdos/todos) is available.

       cvf_format=module
              Forces the driver to use the CVF (Compressed Volume File) module
              cvf_module  instead  of  auto-detection.  If the kernel supports
              kmod, the cvf_format=xxx option also controls on-demand CVF mod-
              ule loading.

       cvf_option=option
              Option passed to the CVF module.

       debug  Turn  on  the  debug  flag.  A version string and a list of file
              system parameters will be printed (these data are  also  printed
              if the parameters appear to be inconsistent).

       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!

       iocharset=value
              Character set to use for converting between 8 bit characters and
              16 bit Unicode characters. The default is iso8859-1.  Long file-
              names are stored on disk in Unicode format.

       quiet  Turn on the quiet flag.  Attempts to chown or chmod files do not
              return errors, although they fail. Use with caution!

       sys_immutable, showexec, dots, nodots, dotsOK=[yes|no]
              Various misguided attempts to force Unix or DOS conventions onto
              a FAT file system.



Mount options for hfs

       creator=cccc, type=cccc
              Set the creator/type values as shown by the  MacOS  finder  used
              for creating new files.  Default values: ’????’.

       uid=n, gid=n
              Set the owner and group of all files.  (Default: the uid and gid
              of the current process.)

       dir_umask=n, file_umask=n, umask=n
              Set the umask used for all directories, all  regular  files,  or
              all files and directories.  Defaults to the umask of the current
              process.

       session=n
              Select the CDROM session to mount.   Defaults  to  leaving  that
              decision  to  the CDROM driver.  This option will fail with any-
              thing but a CDROM as underlying device.

       part=n Select partition number n from the device.  Only makes sense for
              CDROMS.  Defaults to not parsing the partition table at all.

       quiet  Don’t complain about invalid mount options.



Mount options for hpfs

       uid=value and gid=value
              Set  the owner and group of all files. (Default: the uid and gid
              of the current process.)

       umask=value
              Set the umask (the bitmask  of  the  permissions  that  are  not
              present).  The default is the umask of the current process.  The
              value is given in octal.

       case=lower / case=asis
              Convert all files names to lower case, or leave them.  (Default:
              case=lower.)

       conv=binary / conv=text / conv=auto
              For  conv=text,  delete some random CRs (in particular, all fol-
              lowed by NL) when reading a file.  For conv=auto, choose more or
              less   at   random   between  conv=binary  and  conv=text.   For
              conv=binary, just read what is in the file. This is the default.

       nocheck
              Do not abort mounting when certain consistency checks fail.



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
       udf filesystem.)

       Normal  iso9660  filenames  appear  in  a  8.3  format  (i.e., DOS-like
       restrictions on filename length), and in addition all characters are in
       upper  case.   Also  there  is no field for file ownership, protection,
       number of links, provision for block/character devices, etc.

       Rock Ridge is an extension to iso9660 that provides all of  these  unix
       like features.  Basically there are extensions to each directory record
       that supply all of the additional information, and when Rock  Ridge  is
       in  use,  the  filesystem  is indistinguishable from a normal UNIX file
       system (except that it is read-only, of course).

       norock Disable the use of Rock Ridge extensions, even if available. Cf.
              map.

       nojoliet
              Disable  the  use of Microsoft Joliet extensions, even if avail-
              able. Cf. map.

       check=r[elaxed] / check=s[trict]
              With check=relaxed, a filename is first converted to lower  case
              before  doing  the  lookup.   This  is  probably only meaningful
              together with norock and map=normal.  (Default: check=strict.)

       uid=value and gid=value
              Give all files in the file system the indicated  user  or  group
              id,  possibly overriding the information found in the Rock Ridge
              extensions.  (Default: uid=0,gid=0.)

       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 map=off no name  translation  is  done.  See  norock.
              (Default:  map=normal.)   map=acorn  is like map=normal but also
              apply Acorn extensions if present.

       mode=value
              For non-Rock Ridge volumes, give all files the  indicated  mode.
              (Default:  read  permission  for everybody.)  Since Linux 2.1.37
              one no longer needs to specify the mode in  decimal.  (Octal  is
              indicated by a leading 0.)

       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.)

       block=[512|1024|2048]
              Set   the   block   size  to  the  indicated  value.   (Default:
              block=1024.)

       conv=a[uto] / conv=b[inary] / conv=m[text] / conv=t[ext]
              (Default: conv=binary.)  Since Linux 1.3.54 this option  has  no
              effect  anymore.   (And non-binary settings used to be very dan-
              gerous, possibly leading to silent data corruption.)

       cruft  If the high byte of the file length contains other garbage,  set
              this  mount  option  to  ignore  the high order bits of the file
              length.  This implies that a file cannot be larger than 16MB.

       session=x
              Select number of session on multisession CD. (Since 2.3.4.)

       sbsector=xxx
              Session begins from sector xxx. (Since 2.3.4.)

       The following options are the same as for vfat and specifying them only
       makes  sense  when  using discs encoded using Microsoft’s Joliet exten-
       sions.

       iocharset=value
              Character set to use for converting 16 bit Unicode characters on
              CD to 8 bit characters. The default is iso8859-1.

       utf8   Convert 16 bit Unicode characters on CD to UTF-8.



Mount options for jfs

       iocharset=name
              Character  set to use for converting from Unicode to ASCII.  The
              default is to do no conversion.   Use  iocharset=utf8  for  UTF8
              translations.   This  requires  CONFIG_NLS_UTF8 to be set in the
              kernel .config file.

       resize=value
              Resize the volume to value blocks. JFS only supports  growing  a
              volume,  not  shrinking  it.  This option is only valid during a
              remount, when the volume is mounted read-write. The resize  key-
              word  with no value will grow the volume to the full size of the
              partition.

       nointegrity
              Do not write to the journal.  The primary use of this option  is
              to  allow  for  higher  performance when restoring a volume from
              backup media. The integrity of the volume is not  guaranteed  if
              the system abnormally abends.

       integrity
              Default.   Commit  metadata  changes  to  the journal.  Use this
              option to remount a volume where the nointegrity option was pre-
              viously specified in order to restore normal behavior.

       errors=continue / errors=remount-ro / errors=panic
              Define  the  behaviour  when  an  error is encountered.  (Either
              ignore errors and just mark the file system erroneous  and  con-
              tinue,  or  remount the file system read-only, or panic and halt
              the system.)

       noquota / quota / usrquota / grpquota
              These options are accepted but ignored.



Mount options for minix

       None.



Mount options for msdos

       See mount options for fat.  If the msdos file system detects an  incon-
       sistency,  it  reports an error and sets the file system read-only. The
       file system can be made writeable again by remounting it.



Mount options for ncpfs

       Just like nfs, the ncpfs implementation expects a  binary  argument  (a
       struct  ncp_mount_data) to the mount system call. This argument is con-
       structed by ncpmount(8) and the current version of  mount  (2.12)  does
       not know anything about ncpfs.



Mount options for nfs

       Instead  of a textual option string, parsed by the kernel, the nfs file
       system expects a binary argument of type  struct  nfs_mount_data.   The
       program   mount  itself  parses  the  following  options  of  the  form
       ‘tag=value’,  and  puts  them  in  the  structure  mentioned:  rsize=n,
       wsize=n,   timeo=n,   retrans=n,  acregmin=n,  acregmax=n,  acdirmin=n,
       acdirmax=n, actimeo=n, retry=n,  port=n,  mountport=n,  mounthost=name,
       mountprog=n,  mountvers=n,  nfsprog=n, nfsvers=n, namlen=n.  The option
       addr=n is accepted but ignored.  Also the  following  Boolean  options,
       possibly  preceded  by  no  are  recognized:  bg, fg, soft, hard, intr,
       posix, cto, ac, tcp, udp, lock.  For details, see nfs(5).

       Especially useful options include

       rsize=8192,wsize=8192
              This will make your nfs connection faster than with the  default
              buffer  size of 4096. (NFSv2 does not work with larger values of
              rsize and wsize.)

       hard   The program accessing a file on a NFS mounted file  system  will
              hang  when the server crashes. The process cannot be interrupted
              or killed unless you also specify intr.  When the NFS server  is
              back  online the program will continue undisturbed from where it
              was. This is probably what you want.

       soft   This option allows the kernel to time out if the nfs  server  is
              not  responding  for  some  time. The time can be specified with
              timeo=time.  This option might be  useful  if  your  nfs  server
              sometimes doesn’t respond or will be rebooted while some process
              tries to get a file from the server.   Usually  it  just  causes
              lots of trouble.

       nolock Do not use locking. Do not start lockd.



Mount options for nfs4

       Instead of a textual option string, parsed by the kernel, the nfs4 file
       system expects a binary argument of type struct  nfs4_mount_data.   The
       program   mount  itself  parses  the  following  options  of  the  form
       ‘tag=value’,  and  puts  them  in  the  structure  mentioned:  rsize=n,
       wsize=n,   timeo=n,   retrans=n,  acregmin=n,  acregmax=n,  acdirmin=n,
       acdirmax=n, actimeo=n, retry=n, port=n, proto=n,  clientaddr=n,  sec=n.
       The  option addr=n is accepted but ignored.  Also the following Boolean
       options, possibly preceded by no are recognized: bg,  fg,  soft,  hard,
       intr, cto, ac, For details, see nfs(5).

       Especially useful options include

       rsize=32768,wsize=32768
              This  will make your NFS connection faster than with the default
              buffer size of 4096.

       hard   The program accessing a file on a NFS mounted file  system  will
              hang  when the server crashes. The process cannot be interrupted
              or killed unless you also specify intr.  When the NFS server  is
              back  online the program will continue undisturbed from where it
              was. This is probably what you want.

       soft   This option allows the kernel to time out if the NFS  server  is
              not  responding  for  some  time. The time can be specified with
              timeo=time.  This timeout value is expressed in tenths of a sec-
              ond.   The  soft option might be useful if your NFS server some-
              times doesn’t respond or will be  rebooted  while  some  process
              tries  to  get  a file from the server.  Avoid using this option
              with proto=udp or with a short timeout.



Mount options for ntfs

       iocharset=name
              Character set to use when returning file  names.   Unlike  VFAT,
              NTFS  suppresses  names  that  contain unconvertible characters.
              Deprecated.

       nls=name
              New name for the option earlier called iocharset.

       utf8   Use UTF-8 for converting file names.

       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.

       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.

       uid=value, gid=value and umask=value
              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.



Mount options for proc

       uid=value and gid=value
              These options are recognized, but have no effect as far as I can
              see.



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.



Mount options for reiserfs

       Reiserfs  is  a  journaling filesystem.  The reiserfs mount options are
       more fully described at http://www.namesys.com/mount-options.html.

       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.

       hash=rupasov / hash=tea / hash=r5 / hash=detect
              Choose  which  hash  function  reiserfs  will  use to find files
              within directories.

              rupasov
                     A hash invented by Yury Yu. Rupasov.  It is fast and pre-
                     serves  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.

              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 some CPU cost.  This may be used if
                     EHASHCOLLISION errors are experienced with the r5 hash.

              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.

              detect Instructs 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 sys-
                     tem.

       hashed_relocation
              Tunes the block allocator. This may provide performance improve-
              ments in some situations.

       no_unhashed_relocation
              Tunes the block allocator. This may provide performance improve-
              ments in some situations.

       noborder
              Disable the border allocator  algorithm  invented  by  Yury  Yu.
              Rupasov.  This may provide performance improvements in some sit-
              uations.

       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
              nolog is a work in progress.

       notail By  default,  reiserfs  stores  small  files  and  ‘file  tails’
              directly into its tree. This confuses  some  utilities  such  as
              LILO(8).   This  option is used to disable packing of files into
              the tree.

       replayonly
              Replay the transactions which are in the  journal,  but  do  not
              actually mount the file system. Mainly used by reiserfsck.

       resize=number
              A remount option which permits online expansion of reiserfs par-
              titions.  Instructs reiserfs to assume that the device has  num-
              ber  blocks.  This option is designed for use with devices which
              are under logical volume management (LVM).  There is  a  special
              resizer     utility     which     can     be    obtained    from
              ftp://ftp.namesys.com/pub/reiserfsprogs.



Mount options for romfs

       None.



Mount options for smbfs

       Just like nfs, the smbfs implementation expects a  binary  argument  (a
       struct  smb_mount_data) to the mount system call. This argument is con-
       structed by smbmount(8) and the current version of  mount  (2.12)  does
       not know anything about smbfs.



Mount options for sysv

       None.



Mount options for tmpfs

       The  following  parameters  accept  a  suffix  k, m or g for Ki, Mi, Gi
       (binary kilo, mega and giga) and can be changed on remount.

       size=nbytes
              Override default maximum size of the filesystem.   The  size  is
              given  in  bytes, and rounded down to entire pages.  The default
              is half of the memory.

       nr_blocks=
              Set number of blocks.

       nr_inodes=
              Set number of inodes.

       mode=  Set initial permissions of the root directory.



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 iso9660.

       gid=   Set the default group.

       umask= Set the default umask.  The value is given in octal.

       uid=   Set the default user.

       unhide Show otherwise hidden files.

       undelete
              Show deleted files in lists.

       nostrict
              Unset strict conformance.

       iocharset
              Set the NLS character set.

       bs=    Set the block size. (May not work unless 2048.)

       novrs  Skip volume sequence recognition.

       session=
              Set the CDROM session counting from 0. Default: last session.

       anchor=
              Override standard anchor location. Default: 256.

       volume=
              Override the VolumeDesc location. (unused)

       partition=
              Override the PartitionDesc location. (unused)

       lastblock=
              Set the last block of the filesystem.

       fileset=
              Override the fileset block location. (unused)

       rootdir=
              Override the root directory location. (unused)



Mount options for ufs

       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:

              old    Old format of  ufs,  this  is  the  default,  read  only.
                     (Don’t forget to give the -r option.)

              44bsd  For    filesystems   created   by   a   BSD-like   system
                     (NetBSD,FreeBSD,OpenBSD).

              sun    For filesystems created by SunOS or Solaris on Sparc.

              sunx86 For filesystems created by Solaris on x86.

              hp     For filesystems created by HP-UX, read-only.

              nextstep
                     For filesystems created by  NeXTStep  (on  NeXT  station)
                     (currently read only).

              nextstep-cd
                     For NextStep CDROMs (block_size == 2048), read-only.

              openstep
                     For  filesystems  created  by  OpenStep  (currently  read
                     only).  The same filesystem type is also used by  Mac  OS
                     X.


       onerror=value
              Set behaviour on error:

              panic  If an error is encountered, cause a kernel panic.

              [lock|umount|repair]
                     These mount options don’t do anything at present; when an
                     error is encountered only a console message is printed.



Mount options for umsdos

       See mount options for msdos.  The dotsOK option is explicitly killed by
       umsdos.



Mount options for vfat

       First  of  all,  the  mount options for fat are recognized.  The dotsOK
       option is explicitly killed by vfat.  Furthermore, there are

       uni_xlate
              Translate  unhandled  Unicode  characters  to  special   escaped
              sequences.   This lets you backup and restore filenames that are
              created with any Unicode characters. Without this option, a  ’?’
              is used when no translation is possible. The escape character is
              ’:’ because it is otherwise illegal on the vfat filesystem.  The
              escape  sequence  that gets used, where u is the unicode charac-
              ter, is: ’:’, (u & 0x3f), ((u>>6) & 0x3f), (u>>12).

       posix  Allow two files with names that only differ in case.

       nonumtail
              First try to make a short name without sequence  number,  before
              trying name~num.ext.

       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.

       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:

              lower  Force the short name to lower case upon display; store  a
                     long name when the short name is not all upper case.

              win95  Force  the short name to upper case upon display; store a
                     long name when the short name is not all upper case.

              winnt  Display the shortname as is; store a long name  when  the
                     short name is not all lower case or all upper case.

              mixed  Display  the short name as is; store a long name when the
                     short name is not all upper case.

       The default is "lower".



Mount options for usbfs

       devuid=uid and devgid=gid and devmode=mode
              Set the owner and group and mode of  the  device  files  in  the
              usbfs  file  system (default: uid=gid=0, mode=0644). The mode is
              given in octal.

       busuid=uid and busgid=gid and busmode=mode
              Set the owner and group and mode of the bus directories  in  the
              usbfs  file  system (default: uid=gid=0, mode=0555). The mode is
              given in octal.

       listuid=uid and listgid=gid and listmode=mode
              Set the owner and group and mode of the file  devices  (default:
              uid=gid=0, mode=0444). The mode is given in octal.



Mount options for xenix

       None.



Mount options for xfs

       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.

       dmapi  /  xdsm
              Enable the DMAPI (Data Management API) event callouts.

       logbufs=value
              Set  the  number  of in-memory log buffers.  Valid numbers range
              from 2-8 inclusive.  The default value is 8 buffers for filesys-
              tems  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.

       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  mem-
              ory use 16384 by default.

       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 sec-
              tion or contained within it.  Refer to xfs(5).

       noalign
              Data  allocations will not be aligned at stripe unit boundaries.

       noatime
              Access timestamps are not updated when a file is read.

       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.

       nouuid Ignore  the  filesystem  uuid.  This avoids errors for duplicate
              uuids.

       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.

       quota / usrquota / uqnoenforce
              User disk quota  accounting  enabled,  and  limits  (optionally)
              enforced.

       grpquota / gqnoenforce
              Group  disk  quota  accounting  enabled  and limits (optionally)
              enforced.

       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 speci-
              fied, and must be a multiple of the sunit value.



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.  Since Linux version
       2.1.21 xiafs is no longer part of the kernel source.



THE LOOP DEVICE

       One further possible type is a mount via the loop device. For  example,
       the command

         mount /tmp/fdimage /mnt -t msdos -o loop=/dev/loop3,blocksize=1024

       will  set  up  the  loop  device  /dev/loop3  to correspond to the file
       /tmp/fdimage, and then mount this device on /mnt.

       This type of mount knows about three options, namely loop,  offset  and
       encryption,  that are really options to losetup(8).  (These options can
       be used in addition to those specific to the filesystem type.)

       If no explicit loop device is mentioned (but just an option  ‘-o  loop’
       is  given), then mount will try to find some unused loop device and use
       that.  If you are not so unwise as to make /etc/mtab a symbolic link to
       /proc/mounts  then  any loop device allocated by mount will be freed by
       umount.  You can also free a loop device by hand, using  ‘losetup  -d’,
       see losetup(8).



RETURN CODES

       mount has the following return codes (the bits can be ORed):

       0      success

       1      incorrect invocation or permissions

       2      system error (out of memory, cannot fork, no more loop devices)

       4      internal mount bug or missing nfs support in mount

       8      user interrupt

       16     problems writing or locking /etc/mtab

       32     mount failure

       64     some mount succeeded



FILES

       /etc/fstab        file system table

       /etc/mtab         table of mounted file systems

       /etc/mtab~        lock file

       /etc/mtab.tmp     temporary file

       /etc/filesystems  a list of filesystem types to try



SEE ALSO

       mount(2),  umount(2),  fstab(5),  umount(8), swapon(8), nfs(5), xfs(5),
       e2label(8), xfs_admin(8), mountd(8),  nfsd(8),  mke2fs(8),  tune2fs(8),
       losetup(8)


BUGS

       It is possible for a corrupted file system to cause a crash.

       Some Linux file systems don’t support -o sync and -o dirsync (the ext2,
       ext3, fat and vfat file systems do support synchronous  updates  (a  la
       BSD) when mounted with the sync option).

       The  -o remount may not be able to change mount parameters (all ext2fs-
       specific parameters, except sb, are  changeable  with  a  remount,  for
       example, but you can’t change gid or umask for the fatfs).

       Mount  by  label  or uuid will work only if your devices have the names
       listed in /proc/partitions.  In particular, it may  well  fail  if  the
       kernel was compiled with devfs but devfs is not mounted.


HISTORY

       A mount command existed in Version 5 AT&T UNIX.



Linux 2.6                         2004-12-16                          MOUNT(8)

Man(1) output converted with man2html