Updated: October 26, 2022

Unmount a device


umount [-fv] [-T type] path [path ...]

Runs on:

QNX Neutrino


Force an unmount, even if the device is busy.
-T type
Typed umount (not currently supported).
Be verbose.
The root mountpoint to be unmounted.


This utility unmounts the devices that were mounted as the given paths.

If a device is busy (for example, if a file is open), umount fails. You can force the device to be unmounted by specifying the -f option.

In order to use this utility, your process needs to have the vfs/mount-blk (BLK_ABILITY_MOUNTVFS) custom ability enabled. For more information, see procmgr_ability() and procmgr_ability_lookup() in the C Library Reference.