I bought Raspberry Pi and got it up and running. I also happened to have an external HDD which I then mounted to the Raspberry Pi. The mount can be accessed in the /mnt
folder.
I have SD card in the Raspberry Pi which contains the Raspbian operating system. I would like to move the root folder to the external HDD which has much more space than the SD card because all the programs which are installed via apt-get end up on the SD card and fill it up.
However, I haven't found a way to do this and at the moment I'm stuck with this problem.