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MOUNT(8)                FreeBSD System Manager's Manual               MOUNT(8)

     mount - mount file systems

     mount [-adfpruvw] [-t ufs | lfs | external_type]
     mount [-dfpruvw] special | node
     mount [-dfpruvw] [-o options] [-t ufs | lfs | external_type] special node

     The mount command calls the mount(2) system call to prepare and graft a
     special device or the remote node (rhost:path) on to the file system tree
     at the point node.  If either special or node are not provided, the
     appropriate information is taken from the fstab(5) file.

     The system maintains a list of currently mounted file systems.  If no
     arguments are given to mount, this list is printed.

     The options are as follows:

     -a      All the filesystems described in fstab(5) are mounted.
             Exceptions are those marked as ``noauto'', excluded by the -t
             flag (see below), or if they are already mounted (except the root
             filesystem which is always remounted to preserve traditional
             single user mode behavior).

     -d      Causes everything to be done except for the actual system call.
             This option is useful in conjunction with the -v flag to
             determine what the mount command is trying to do.

     -f      Forces the revocation of write access when trying to downgrade a
             filesystem mount status from read-write to read-only. Also forces
             the R/W mount of an unclean filesystem (dangerous; use with

     -o      Options are specified with a -o flag followed by a comma
             separated string of options.  The following options are

             async   All I/O to the file system should be done asynchronously.
                     This is a dangerous flag to set, and should not be used
                     unless you are prepared to recreate the file system
                     should your system crash.

             force   The same as -f; forces the revocation of write access
                     when trying to downgrade a filesystem mount status from
                     read-write to read-only. Also forces the R/W mount of an
                     unclean filesystem (dangerous; use with caution).

                     Do not update the file access time when reading from a
                     file. This option is useful on filesystems where there
                     are large numbers of files and performance is more
                     critical than updating the file access time (which is
                     rarely ever important). This option is currently only
                     supported on local filesystems.

             noauto  This filesystem should be skipped when mount is run with
                     the -a flag.

                     Disable read clustering.

                     Disable write clustering.

             nodev   Do not interpret character or block special devices on
                     the file system.  This option is useful for a server that
                     has file systems containing special devices for
                     architectures other than its own.

             noexec  Do not allow execution of any binaries on the mounted
                     file system.  This option is useful for a server that has
                     file systems containing binaries for architectures other
                     than its own.

             nosuid  Do not allow set-user-identifier or set-group-identifier
                     bits to take effect.  Note: this option is worthless if a
                     public available suid or sgid wrapper like suidperl(1) is
                     installed on your system.

                     Do not follow symlinks on the mounted file system.

             rdonly  The same as -r; mount the file system read-only (even the
                     super-user may not write it).

             sync    All I/O to the file system should be done synchronously.

                     A directory on the mounted filesystem will respond to the
                     SUID bit being set, by setting the owner of any new files
                     to be the same as the owner of the directory.  New
                     directories will inherit the bit from their parents.
                     Execute bits are removed from the file, and it will not
                     be given to root.

                     This feature is designed for use on fileservers serving
                     PC users via ftp, SAMBA, or netatalk. It provides
                     security holes for shell users and as such should not be
                     used on shell machines, especially on home directories.
                     This option requires the SUIDDIR option in the kernel to
                     work. Only UFS filesystems support this option.  See
                     chmod(2) for more information.

             update  The same as -u; indicate that the status of an already
                     mounted file system should be changed.

             union   Causes the namespace at the mount point to appear as the
                     union of the mounted filesystem root and the existing
                     directory.  Lookups will be done in the mounted
                     filesystem first.  If those operations fail due to a non-
                     existent file the underlying directory is then accessed.
                     All creates are done in the mounted filesystem.

             Any additional options specific to a filesystem type that is not
             one of the internally known types (see the -t option) may be
             passed as a comma separated list; these options are distinguished
             by a leading ``-'' (dash).  Options that take a value are
             specified using the syntax -option=value.  For example, the mount

                   mount -t mfs -o nosuid,-N,-s=4000 /dev/dk0b /tmp

             causes mount to execute the equivalent of:

                   /sbin/mount_mfs -o nosuid -N -s 4000 /dev/dk0b /tmp

     -p      Print mount information in fstab format. Implies also the -v

     -r      The file system is to be mounted read-only.  Mount the file
             system read-only (even the super-user may not write it).  The
             same as the ``rdonly'' argument to the -o option.

     -t ufs \*(Ba lfs \*(Ba external type
             The argument following the -t is used to indicate the file system
             type.  The type ufs is the default.  The -t option can be used to
             indicate that the actions should only be taken on filesystems of
             the specified type.  More than one type may be specified in a
             comma separated list.  The list of filesystem types can be
             prefixed with ``no'' to specify the filesystem types for which
             action should not be taken.  For example, the mount command:

                   mount -a -t nonfs,mfs

             mounts all filesystems except those of type NFS and MFS.

             If the type is not one of the internally known types, mount will
             attempt to execute a program in /sbin/mount_XXX where XXX is
             replaced by the type name.  For example, nfs filesystems are
             mounted by the program /sbin/mount_nfs.

             Most filesystems will be dynamically loaded by their mount
             programs if not already present in the kernel, using the
             vfsload(3) subroutine.  Because this mechanism requires writable
             temporary space, the filesystem type containing /tmp must be
             compiled into the kernel, and the filesystems containing /tmp and
             /usr/bin/ld must be listed in /etc/fstab before any filesystems
             which might be dynamically loaded.

     -u      The -u flag indicates that the status of an already mounted file
             system should be changed.  Any of the options discussed above
             (the -o option) may be changed; also a file system can be changed
             from read-only to read-write or vice versa.  An attempt to change
             from read-write to read-only will fail if any files on the
             filesystem are currently open for writing unless the -f flag is
             also specified.  The set of options is determined by first
             extracting the options for the file system from the fstab(5)
             table, then applying any options specified by the -o argument,
             and finally applying the -r or -w option.

     -v      Verbose mode.

     -w      The file system object is to be read and write.

             The options specific to NFS filesystems are described in the
             mount_nfs(8) manual page.

     Various, most of them are self-explanatory.

           XXXXX filesystem is not available

     The kernel doesn't support the respective filesystem type.  Note that
     support for a particular filesystem might be provided either on a static
     (kernel compile-time), or dynamic basis (loaded as a kernel module by
     kldload(8) ). Normally, mount or its subprocesses attempt to dynamically
     load a filesystem module if it hasn't been configured statically, using
     vfsload(3).  In this case, the above error message can also mean that you
     didn't have permission to load the module.

     /etc/fstab  file system table

     mount(2), vfsload(3), fstab(5), kldload(8), mount_cd9660(8),
     mount_devfs(8), mount_fdesc(8), mount_kernfs(8), mount_lfs(8),
     mount_mfs(8), mount_msdos(8), mount_nfs(8), mount_null(8),
     mount_portal(8), mount_procfs(8), mount_umap(8), mount_union(8),

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

     Switching a filesystem back and forth between asynchronous and normal
     operation or between read/write and read/only access using ``mount -u''
     may gradually bring about severe filesystem corruption.

     After a successful mount, the permissions on the original mount point
     determine if .. is accessible from the mounted file system.  The minimum
     permissions for the mount point for traversal across the mount point in
     both directions to be possible for all users is 0111 (execute for all).

     A mount command appeared in Version 1 AT&T UNIX.

BSD 4                            June 16, 1994                           BSD 4


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