v7 man page for umount

mount(1M)						  System Administration Commands						 mount(1M)

NAME
       mount, umount - mount or unmount file systems and remote resources

SYNOPSIS
       mount [-p | -v]

       mount [-F FSType] [generic_options] [-o specific_options] [-O] special | mount_point

       mount [-F FSType] [generic_options] [-o specific_options] [-O] special mount_point

       mount -a [-F FSType] [-V] [current_options] [-o specific_options] [mount_point...]

       umount [-f] [-V] [-o specific_options] special | mount_point

       umount -a [-f] [-V] [-o specific_options] [mount_point...]

DESCRIPTION
       mount  attaches a file system to the file system hierarchy at the mount_point, which is the pathname of a directory. If mount_point has any
       contents prior to the mount operation, these are hidden until the file system is unmounted.

       umount unmounts a currently mounted file system, which may be specified either as a mount_point or as special, the device on which the file
       system resides.

       The  table of currently mounted file systems can be found by examining the mounted file system information file. This is provided by a file
       system that is usually mounted on /etc/mnttab. The mounted file system information is described in mnttab(4). Mounting a file  system  adds
       an entry to the mount table; a umount removes an entry from the table.

       When  invoked  with  both  the  special	and  mount_point arguments and the -F option, mount validates all arguments except for special and
       invokes the appropriate FSType-specific mount module. If invoked with no arguments, mount lists all the mounted file  systems  recorded	in
       the  mount  table,  /etc/mnttab.  If invoked with a partial argument list (with only one of special or mount_point, or with both special or
       mount_point specified but not FSType), mount will search /etc/vfstab for an entry that will supply the missing arguments. If  no  entry	is
       found,  and  the  special argument starts with "/", the default local file system type specified in /etc/default/fs will be used. Otherwise
       the default remote file system type will be used.  The  default	remote	file  system  type  is	determined  by	the  first  entry  in  the
       /etc/dfs/fstypes file.  After filling in missing arguments, mount will invoke the FSType-specific mount module.

       Only  a	super-user  can mount or unmount file systems using mount and umount. However, any user can use mount to list mounted file systems
       and resources.

OPTIONS
       -F FSType

	   Used to specify the FSType on which to operate. The FSType must be specified or must be determinable from /etc/vfstab, or by consulting
	   /etc/default/fs or /etc/dfs/fstypes.

       -a [ mount_points. . . ]

	   Perform mount or umount operations in parallel, when possible.

	   If  mount points are not specified, mount will mount all file systems whose /etc/vfstab "mount at boot" field is "yes". If mount points
	   are specified, then /etc/vfstab "mount at boot" field will be ignored.

	   If mount points are specified, umount will only umount those mount points. If none is specified, then umount will  attempt  to  unmount
	   all	file systems in /etc/mnttab, with the exception of certain system required file systems: /, /usr, /var, /var/adm, /var/run, /proc,
	   /dev/fd and /tmp.

       -f

	   Forcibly unmount a file system.

	   Without this option, umount does not allow a file system to be unmounted if a file on the file system is busy. Using  this  option  can
	   cause data loss for open files; programs which access files after the file system has been unmounted will get an error (EIO).

       -p

	   Print the list of mounted file systems in the /etc/vfstab format. Must be the only option specified. See BUGS.

       -v

	   Print the list of mounted file systems in verbose format. Must be the only option specified.

       -V

	   Echo the complete command line, but do not execute the command. umount generates a command line by using the options and arguments pro-
	   vided by the user and adding to them information derived from /etc/mnttab.  This option should be used to verify and validate the  com-
	   mand line.

       generic_options

	   Options that are commonly supported by most FSType-specific command modules. The following options are available:

	   -m

	       Mount the file system without making an entry in /etc/mnttab.

	   -g

	       Globally  mount the file system. On a clustered system, this globally mounts the file system on all nodes of the cluster. On a non-
	       clustered system this has no effect.

	   -o

	       Specify FSType-specific options in a comma separated (without spaces) list of suboptions and keyword-attribute pairs for  interpre-
	       tation  by  the FSType-specific module of the command. (See mount_ufs(1M).) When you use -o with a file system that has an entry in
	       /etc/vfstab, any mount options entered for that file system in /etc/vfstab are ignored.

	       The following options are supported:

	       devices | nodevices

		   Allow or disallow the opening of device-special files. The default is devices.

		   If you use nosuid in conjunction with devices, the behavior is equivalent to that of nosuid.

	       exec | noexec

		   Allow or disallow executing programs in the file system. Allow or disallow mmap(2) with PROT_EXEC for  files  within  the  file
		   system. The default is exec.

	       nbmand | nonbmand

		   Allow or disallow non-blocking mandatory locking semantics on this file system. Non-blocking mandatory locking is disallowed by
		   default.

		   If the file system is mounted with the nbmand option, then applications can use the fcntl(2) interface  to  place  non-blocking
		   mandatory  locks on files and the system enforces those semantics. If you enable this option, it can cause standards conformant
		   applications to see unexpected errors.

		   Do not use the nbmand option with /, /var and /usr.

		   You should not use the remount option to change the nbmand disposition of the file system. The nbmand option is mutually exclu-
		   sive of the global option. See -g.

	       ro | rw

		   Specify read-only or read-write. The default is rw.

	       setuid | nosetuid

		   Allow or disallow setuid or setgid execution. The default is setuid.

		   If you specify setuid in conjunction with nosuid, the behavior is the same as nosuid.

		   nosuid  is  equivalent  to nosetuid and nodevices. When suid or nosuid is combined with setuid or nosetuid and devices or node-
		   vices, the most restrictive options take effect.

		   This option is highly recommended whenever the file system is shared by way of NFS with  the  root=	option.  Without  it,  NFS
		   clients could add setuid programs to the server or create devices that could open security holes.

	       suid | nosuid

		   Allow or disallow setuid or setgid execution. The default is suid. This option also allows or disallows opening any device-spe-
		   cial entries that appear within the filesystem.

		   nosuid is equivalent to nosetuid and nodevices. When suid or nosuid is combined with setuid or nosetuid and	devices  or  node-
		   vices, the most restrictive options take effect.

		   This  option  is highly recommended whenever the file system is shared using NFS with the root=option, because, without it, NFS
		   clients could add setuid programs to the server, or create devices that could open security holes.

	   -O

	       Overlay mount. Allow the file system to be mounted over an existing mount point, making the underlying file system inaccessible. If
	       a  mount  is  attempted	on  a pre-existing mount point without setting this flag, the mount will fail, producing the error "device
	       busy".

	   -r

	       Mount the file system read-only.

USAGE
       See largefile(5) for the description of the behavior of mount and umount when encountering files greater than or equal to 2 Gbyte ( 2 **31
       bytes).

FILES
       /etc/mnttab	       Table of mounted file systems.

       /etc/default/fs	       Default	local file system type. Default values can be set for the following flags in /etc/default/fs. For example:
			       LOCAL=ufs

			       LOCAL:	The default partition for a command if no FSType is specified.

       /etc/vfstab	       List of default parameters for each file system.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       mount_cachefs(1M), mount_hsfs(1M), mount_nfs(1M), mount_pcfs(1M), mount_tmpfs(1M), mount_ufs(1M),  mountall(1M),  umountall(1M),  fcntl(2),
       mmap(2), mnttab(4), vfstab(4), attributes( 5), largefile(5), lofs(7FS), pcfs(7FS)

NOTES
       If  the directory on which a file system is to be mounted is a symbolic link, the file system is mounted on the directory to which the sym-
       bolic link refers, rather than on top of the symbolic link itself.

BUGS
       The mount -p output is incorrect for cachefs.

SunOS 5.10							    1 Jul 2004								 mount(1M)