xubuntu@xubuntu:~$ sudo umount /dev/sda2 
umount: /dev/sda2: not mounted
xubuntu@xubuntu:~$ mkdir /media/a
mkdir: cannot create directory ‘/media/a’: Permission denied
xubuntu@xubuntu:~$ sudo mount /dev/sda2 /media/a 
ntfs-3g-mount: failed to access mountpoint /media/a: No such file or directory
xubuntu@xubuntu:~$ ls -la /media/a | pastebinit 
ls: cannot access /media/a: No such file or directory
You are trying to send an empty document, exiting.
xubuntu@xubuntu:~$