UMOUNT(8) BSD System Manager's Manual UMOUNT(8)NAMEumount — unmount filesystems
SYNOPSISumount [-fvFR] [-t fstypelist] special | node
umount-a [-fvF] [-h host] [-t fstypelist]
DESCRIPTION
The umount command calls the unmount(2) system call to remove a special
device or the remote node (rhost:path) from the filesystem tree at the
point node. If either special or node are not provided, the appropriate
information is taken from the fstab(5) file.
The options are as follows:
-a All the currently mounted filesystems except the root are
unmounted.
-f The filesystem is forcibly unmounted. Active special devices
continue to work, but all other files return errors if further
accesses are attempted. The root filesystem cannot be forcibly
unmounted.
-F Fake the unmount; perform all other processing but do not actu‐
ally attempt the unmount. (This is most useful in conjunction
with -v, to see what umount would attempt to do).
-R Take the special | node argument as a path to be passed directly
to unmount(2), bypassing all attempts to be smart about mechani‐
cally determining the correct path from the argument. This
option is incompatible with any option that potentially unmounts
more than one filesystem, such as -a, but it can be used with -f
and/or -v. This is the only way to unmount something that does
not appear as a directory (such as a nullfs mount of a plain
file); there are probably other cases where it is necessary.
-h host
Only filesystems mounted from the specified host will be
unmounted. This option is implies the -a option and, unless oth‐
erwise specified with the -t option, will only unmount NFS
filesystems.
-t fstypelist
Is used to indicate the actions should only be taken on filesys‐
tems 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 umount command:
umount-a -t nfs,mfs
unmounts all filesystems of the type NFS and MFS, whereas the
umount command:
umount-a -t nonfs,mfs
unmounts all file systems except those of type NFS and MFS.
-v Verbose, additional information is printed out as each filesystem
is unmounted.
FILES
/etc/fstab filesystem table
SEE ALSOunmount(2), fstab(5), mount(8)HISTORY
A umount command appeared in Version 6 AT&T UNIX.
BSD May 17, 2009 BSD