# umount > Unlink a filesystem from its mount point, making it no longer accessible. > A filesystem cannot be unmounted when it is busy. > More information: . - Unmount a filesystem, by passing the path to the source it is mounted from: `umount {{path/to/device_file}}` - Unmount a filesystem, by passing the path to the target where it is mounted: `umount {{path/to/mounted_directory}}` - Unmount all mounted filesystems (except the `proc` filesystem): `umount -a`