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Jason
Asked: 2012-05-20 19:08:56 +0800 CST

Update MBR of new drive after cloning

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I just cloned the Linux partition of my laptop to be used on the desktop.

However, this was just a straight DD execution, and the MBR of the new drive is not affected. How can I change the new drive to be bootable?

The exact DD command I used was dd if=/dev/sda5 of=/dev/sdc5

backup bootloader dd

1 Answers

  1. Let's assume that :

    • Your destination partition table is correctly defined
    • Sizes of sda5 and sdc5 matches (otherwise it would not make sense, or you will need to run gparted to resize the filesystem if sda5 is smaller than sdc5)

    You will probably want to copy just the first 440 bytes of the MBR since the partition table is whithin the MBR sector (see wikipedia entries (en) or (fr) with dd command examples).

    dd if=/dev/sda of=/dev/sdc bs=1 count=440

    Anyway, gparted allows you to easily and quickly copy data between partitions since it analyzes filesystems and only copies the bytes needed, so I would recommend gparted against dd.

    The only exception would be in the case you want to recover a broken drive, in that case I would recommend you to extract data with dd_rescue which is more resilient to errors than dd, probably faster, too.

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