Clone Hard Drive to External USB Drive via CLI

Thumb and USB drives

No matter what OS you’re cloning, using “dd” via command line will still work.  I personally tested while cloning a 1TB Ubuntu hard drive to a fancy new 1TB SSD.

Backstory: I purchased a new Dell 7737 laptop with a 1TB hybrid drive, which turned out to be slower than watching paint dry compared to the old SSD I’d been using for a few years.  Otherwise it is a kickass laptop.  So I purchased a 1TB SSD after finding they are roughly 50 cents per GB these days…very affordable.

First I put the new SSD into USB caddy I had laying around for backup purposes.

Next I created a bootable USB stick with an Ubuntu ISO image following the instructions at:

Windows =
Ubuntu =

With the USB stick created I booted the system to Ubuntu using the USB LiveCD disk image.  It may require a BIOS change to enable the PC/Laptop to boot from USB device.  Doing this will not make any changes to your current hard drive as long as “Install Ubuntu” is not chosen.

Once booted up I was able to use Gparted, which is a standard app on the LiveCD, to create a new partition table on the new drive in the external USB caddy.

I then used fdisk via command line to find all disks and gain their identifiers needed.

fdisk -l

With the new partition and the identifier of the USB drive I was now ready to initiate the copy.  I used the following command to do that:

dd if=/dev/sdc of=/dev/sdb mb=8M && sync

NOTE: ‘if’ = read from and ‘of’ = write to.

It takes a very long time for this to finish up, especially with larger drives, but the end result was a working drive with my data on it.

After completion I simply switched out the SSD from the caddy with the internal HD in the laptop and all worked well.

Good luck!

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Application Architect from Florida

2 thoughts on “Clone Hard Drive to External USB Drive via CLI”

  1. You did not mention which OS you have cloned.

    In the case of Linux I doubt that the new cloned system will work.
    (even if it would serve as a backup)

    Possibly you’d make many changes to all the files that contain a reference to the original disk/partition to get it work…
    (or even complete the boot)

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