Copying MBR

I’ve been doing some disk partitions cloning between disks of different size. I needed to copy the master boot record (MBR), where LILO is, from one disk to another. I searched a bit and found a handy tutorial.

As the web-site explains, the MBR size has the following structure: 446B Bootstrap + 64B Partition table + 2B Signature = 512B. So, to copy the MBR to another disk, preserving its partitioning schema I did the following:

Copy the MBR to a file in /tmp:

dd if=/dev/sda of=/tmp/mbrsda.bak bs=512 count=1

Then, clone the image to the other disk with a different partition scheme:

dd if=/tmp/mbrsda.bak of=/dev/sdb bs=446 count=1

That’s it!