unmout - invalid argument ??
by jan128 from LinuxQuestions.org on  (#5BXRR)
	I made an error applying "mount" and now I cannot use "umount" .
What am I doing wrong?
Code:
sdl 8:176 1 28.9G 0 disk
sdl1 8:177 1 9.8G 0 part /media/c/sdl
sdl2 8:178 1 9.8G 0 part /media/c/sdl
c@c-SATA:~$ sudo umount /dev/sdl
umount: /dev/sdl: not mounted
c@c-SATA:~$ sudo umount /dev/sdl1
umount: /dev/sdl1: umount failed: Invalid argument
c@c-SATA:~$
 
 
 
 

	
What am I doing wrong?
Code:
sdl 8:176 1 28.9G 0 disk
sdl1 8:177 1 9.8G 0 part /media/c/sdl
sdl2 8:178 1 9.8G 0 part /media/c/sdl
c@c-SATA:~$ sudo umount /dev/sdl
umount: /dev/sdl: not mounted
c@c-SATA:~$ sudo umount /dev/sdl1
umount: /dev/sdl1: umount failed: Invalid argument
c@c-SATA:~$