umount
TLDR
Unmount a filesystem by device path
$ sudo umount [path/to/device]
Unmount a filesystem by mount point$ sudo umount [path/to/mounted_directory]
Remount read-only when unmount fails$ sudo umount -r [path/to/mounted_directory]
Recursively unmount each directory$ sudo umount -R [path/to/mounted_directory]
Unmount all mounted filesystems (except proc)$ sudo umount -a
SYNOPSIS
umount [options] target...
DESCRIPTION
umount detaches a filesystem from its mount point, making it no longer accessible. The filesystem can be specified by its source device or mount point directory.
A filesystem cannot be unmounted while it is "busy" - that is, while files on it are open or processes have their working directory there. Use lsof or fuser to find processes using the filesystem.
PARAMETERS
-a, --all
Unmount all filesystems (except proc)-r, --read-only
If unmount fails, try to remount read-only-R, --recursive
Recursively unmount directories-l, --lazy
Lazy unmount (detach now, cleanup later)-f, --force
Force unmount (for unreachable NFS)-n, --no-mtab
Don't write to /etc/mtab-t, --types _type_
Unmount only filesystems of specified type-v, --verbose
Verbose mode
CAVEATS
Requires root privileges unless the user option was specified in fstab. Busy filesystems cannot be unmounted normally. Lazy unmount (-l) can leave filesystem in inconsistent state. Force unmount (-f) only works for NFS. Part of the util-linux package.
