DD to clone / copy partition to new disk

Backup MBR
dd if=/dev/sda of=/mnt/boot/sda.mbr bs=512 count=1

Restore MBR
dd if=/mnt/boot/sda.mbr of=/dev/sdb bs=512 count=1

Fdisk to change any partitions on new sdb

Then copy first partition

dd if=/dev/sda1 of=/dev/sdb2 conv=noerror,sync