NAME¶
umount —
unmount file systems
SYNOPSIS¶
umount |
[-fv] special
... | node ... | fsid
... |
umount |
-a | -A
[-fv]
[-h host]
[-t
type] |
DESCRIPTION¶
The
umount utility calls the
unmount(2)
system call to remove a file system from the file system tree. The file system
can be specified by its
special device or remote node
(rhost:path), the path to the mount point
node or by the
file system ID
fsid as reported by “mount
-v” when run by root.
The options are as follows:
- -a
- All the file systems described in
fstab(5) are unmounted.
- -A
- All the currently mounted file systems except the root are
unmounted.
- -f
- The file system is forcibly unmounted. Active special
devices continue to work, but all other files return errors if further
accesses are attempted. The root file system cannot be forcibly unmounted.
For NFS, a forced dismount can take up to 1 minute or more to complete
against an unresponsive server and may throw away data not yet written to
the server for this case.
- -h
host
- Only file systems mounted from the specified host will be
unmounted. This option implies the -A option and, unless
otherwise specified with the -t option, will only
unmount NFS file systems.
- -t
type
- Is used to indicate the actions should only be taken on
file systems of the specified type. 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 for which action should
not be taken. For example, the umount
command:
unmounts all file systems of the type NFS and NULLFS that are listed in the
fstab(5) file.
- -v
- Verbose, additional information is printed out as each file
system is unmounted.
ENVIRONMENT¶
PATH_FSTAB
- If the environment variable
PATH_FSTAB
is set, all operations are performed
against the specified file. PATH_FSTAB
will not be
honored if the process environment or memory address space is considered
“tainted”. (See issetugid(2) for more
information.)
FILES¶
- /etc/fstab
- file system table
SEE ALSO¶
unmount(2),
fstab(5),
mount(8)
HISTORY¶
A
umount utility appeared in
Version 6
AT&T UNIX.