umount, unmount

PURPOSE

     Unmounts a previously mounted  file system, directory, or
     file.

SYNOPSIS
     umount [ all ] [ directory ] [ [ -s ] device ]

     unmount [ all ] [ directory ] [ [ -s ] device ]

DESCRIPTION

     The  umount command  unmounts a  previously mounted  file
     system,  directory,  or  file.  Processing  on  the  file
     system, directory, or file completes and it is unmounted.
     Members  of the  system  group and  users operating  with
     superuser authority can issue  any umount command.  Other
     users  can unmount  any directory  or file  if they  have
     write permission  to the mounted over  directory or file.
     For local mounts, you can specify the file system, direc-
     tory, or file as either  the directory or device on which
     it is mounted.

       You can also specify one of the following parameters:

     all       Unmounts all mounted file systems.
     allr      Unmounts all remote mounted file systems.

     Note:  For  remote mounts,  specify the directory  of the
     file as directory.  If  you specify allr, umount unmounts
     all remote mounts.

FLAGS

     -f        Forces  the  unmount  of one  or  more  virtual
               filesystems.   Use  in a  distributed  services
               environment to free a client when the server is
               down and server pathnames cannot be resolved.
     -n node   Specifies  the  node  which holds  the  mounted
               directory that  you want to unmount.   node can
               be either a nickname or  a node ID.  The umount
               -n node command unmounts all remote mounts made
               from node.
     -s device Prohibits the use of the /etc/mnttab file if it
               is damaged  or not  writable.  If you  use this
               flag, you  must specify the name  of the device
               to be unmounted.

     -t type   Unmounts all  stanzas in  /etc/filesystems that
               contain type = type  and are mounted.  (type is
               a string value, such as "remote".)

     Note:  You cannot use the umount command on a device that
     is in use.   A device is in  use if any file  is open for
     any reason  or if a  user's current directory is  on that
     device.

EXAMPLES

     1.  To unmount a diskette drive:

           umount /dev/fd0

     2.  To unmount the device mounted on /diskette0:

           umount /diskette0

     3.  To unmount all mounts from a remote node:

           umount -n nodeA

     4.  To unmount files and directories of a specifc type:

           umount -t remote

         This unmounts  all files  or directories that  have a
         stanza in the /etc/filesystems file that contains the
         attribute "type = remote".

FILES

     /etc/filesystems    Descriptions   of    mountable   file
                         systems.
     /etc/mnttab         Table   of  currently   mounted  file
                         systems.

RELATED INFORMATION

     The following command:  "mount."

     The  mount, umount,  vmount, uvmount,  and mntctl  system
     calls and the  mnttab file in AIX  Operating System Tech-
     nical Reference.