How to mount vdi file to Linux!?

First install QEMU on Ubuntu: 

sudo apt-get install qemu

Then run these: 

sudo modprobe nbd 

         // create net disks

sudo qemu-nbd -c /dev/nbd0 /media/ 
         // locate the vdi as a net disk

sudo mount /dev/nbd0 /home/

         // mount the net disk to directory