I did something very stupid.. I wanted to overwrite my MBR of my usb disk and executed the following commands..
sudo dd if=./boot0 of=/dev/sdb bs=1b count=1
sudo dd if=./boot1h of=/dev/sdb2
Now I can't list the partitions(6 partitions) in sdb. Any suggestions? I have ubuntu in /dev/sda
install-mbr /dev/sdb
Dint help either.