unmount file systems
umount command calls the
unmount(2) system call to remove a special
device or node ([rhost:]
path) from the file system tree. Multiple devices and
nodes may be specified on the command line. If neither
special nor node are provided,
the appropriate information is taken from the kernel.
The options are as follows:
- All of the file systems except root returned by getmntinfo(3) are unmounted.
- 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.
- Only filesystems mounted from the specified host will be unmounted. This
option implies the
-aoption and, unless otherwise specified with the
-toption, will only unmount NFS filesystems.
- Indicates that 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
taken. For example, the following command unmounts all filesystems of type
NFS and MFS:
# umount -a -t nfs,mfs
- Verbose, additional information is printed out as each file system is unmounted.
unmount(2), getmntinfo(3), mount(8)
umount command appeared in
Version 1 AT&T UNIX.