UMOUNT(8) BSD System Manager's Manual UMOUNT(8)
umount - unmount filesystems
umount [-fv] special | node umount -a [-fv] [-h host] [-t ufs | lfs | external_type]
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 neither special nor node are provided, the appropriate in- formation is taken from the fstab(5) file. The options are as follows: -a All of the filesystems described in fstab(5) are unmounted. -f The filesystem is forcibly unmounted. Active special devices con- tinue to work, but all other files return errors if further accesses are attempted. The root filesystem cannot be forcibly unmounted. -h host Only filesystems mounted from the specified host will be unmount- ed. This option implies the -a option and, unless otherwise specified with the -t option, will only unmount NFS filesystems. -t ufs | lfs | external type 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 ac- tion should not be taken. For example, the umount command: # umount -a -t nfs,mfs umounts all filesystems of the type NFS and MFS. -v Verbose, additional information is printed out as each filesystem is unmounted.
/etc/fstab filesystem table
unmount(2), fstab(5), mount(8)
A umount command appeared in Version 3 AT&T UNIX. MirBSD #10-current February 20, 1994 1