I have a Sony VIAO laptop setup as dual boot (Ubuntu 12.10/Windows 7). Since I wanted to try Archlinux, I installed VirtualBox in Ubuntu. To create a bootable USB stick (from the ISO image on my hard drive), I followed the instructions from archlinux installation guide. However, accidentally gave the following command:
sudo dd bs=4M if=/path/to/archlinux.iso of=/dev/sda && sync
/dev/sda instead of
/dev/sdb. So the MBR was overwritten here. BAD mistake. Did not realise the mistake at that time and tried to install archlinux in the virtualbox (allocated 8GB of disk space), couldn't complete the process and shutdown.
Now, after booting, I get the first screen of the archlinux installation process.
df only shows various partitions made during the archlinux installation process of 8GB of the total 320 GB harddisk.
I had not taken any backup of the MBR. Is there a way to restore the MBR or salvage some data?