Unmount a device
umount [-fv] [-T type] path [path ...]
QNX Neutrino
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.