Mac Developer Library Developer
Search

 

This manual page is for Mac OS X version 10.9

If you are running a different version of Mac OS X, view the documentation locally:

  • In Terminal, using the man(1) command

Reading manual pages

Manual pages are intended as a quick reference for people who already understand a technology.

  • To learn how the manual is organized or to learn about command syntax, read the manual page for manpages(5).

  • For more information about this technology, look for other documentation in the Apple Developer Library.

  • For general information about writing shell scripts, read Shell Scripting Primer.




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

NAME
     mount -- mount file systems

SYNOPSIS
     mount [-adfruvw] [-t lfs | external_type]
     mount [-dfruvw] special | node
     mount [-dfruvw] [-o options] [-t lfs | external_type] special node

DESCRIPTION
     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 pro-vided, provided,
     vided, the appropriate information is obtained via the getfsent(3) library routines.

     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 listed via getfsent(3) are mounted.  Exceptions are those marked as
             ``noauto;'' excluded by the -t flag (see below); entries that are neither ``ro,'' ``rw,'' or
             ``rq;'' ``nfs'' entries that also have ``net'' as an option; and already-mounted ``nfs''
             entries.

     -d      Causes everything to be done except for the actual system call.  This option is useful in con-junction conjunction
             junction 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.

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

             async   All I/O to the file system should be done asynchronously.  This can be somewhat danger-ous dangerous
                     ous with respect to losing data when faced with system crashes and power outages.  This
                     is also the default.  It can be avoided with the noasync option.

             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.

             noasync
                     This filesystem should not force all I/O to be written asynchronously.

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

             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 use-ful useful
                     ful for a server that has file systems containing binaries for architectures other than
                     its own.

             noowners
                     Ignore the ownership field for the entire volume.  This causes all objects to appear as
                     owned by user ID 99 and group ID 99.  User ID 99 is interpreted as the current effec-tive effective
                     tive user ID, while group ID 99 is used directly and translates to ``unknown''.

             nosuid  Do not allow set-user-identifier or set-group-identifier bits to take effect.

             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.

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

             union   Causes the namespace to appear as the union of directories of the mounted filesystem
                     with corresponding directories in the underlying filesystem.  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.

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

             nobrowse
                     This option indicates that the mount point should not be visible via the GUI (i.e.,
                     appear on the Desktop as a separate volume).

             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 distin-guished distinguished
             guished by a leading ``-'' (dash).  Options that take a value are specified using the syntax
             -option=value.  For example, the mount command:

                   mount -t hfs -o nosuid,-w,-m=755 /dev/disk2s9 /tmp

             causes mount to execute the equivalent of:

                   /sbin/mount_hfs -o nosuid -w -m 755 /dev/disk2s9 /tmp

     -r      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 lfs | external type
             The argument following the -t is used to indicate the file system type.  There is no default
             local file system for use with mount. A type must be specified in order to mount a non-NFS
             filesystem.  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,hfs

             mounts all filesystems except those of type NFS and HFS.

             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.

     -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 filesystem table (see getfsent(3)) then applying any options specified
             by the -o argument, and finally applying the -r or -w option.

     -v      Verbose mode.

     -w      Mount the file system read-write.

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

SEE ALSO
     mount(2), getfsent(3), mount_afp(8), mount_cd9660(8), mount_cddafs(8), mount_fdesc(8), mount_hfs(8),
     mount_msdos(8), mount_nfs(8), mount_smbfs(8), mount_udf(8), mount_webdav(8), umount(8)

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

HISTORY
     A mount command appeared in Version 6 AT&T UNIX.

4th Berkeley Distribution        June 16, 1994       4th Berkeley Distribution

Reporting Problems

The way to report a problem with this manual page depends on the type of problem:

Content errors
Report errors in the content of this documentation with the feedback links below.
Bug reports
Report bugs in the functionality of the described tool or API through Bug Reporter.
Formatting problems
Report formatting mistakes in the online version of these pages with the feedback links below.

Feedback