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Clone a Hard Drive

Introduction

To clone a disk under Windows, you need to pull out all the tools, and if it's bootable, then hold on tight... how much does it cost? Obviously, Windows purist pirates will tell me they download a cracked version.

Why use such tools and break the law when free and amazing tools exist? Let's take a look at some options...

Solutions

dd

dd is the ultimate solution. To duplicate a disk with a progress bar:

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dd if=/dev/sda2 of=/dev/sdb2 bs=4096 conv=notrunc,noerror | bar -s 500g

Here I'm copying a 500g hard drive. For those who don't want to use the bar command:

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dd if=/dev/sda2 of=/dev/sdb2 bs=4096 conv=notrunc,noerror &
watch -n5 -- pkill -USR1 ^dd$

To clone a disk remotely:

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dd if=/dev/vgname/lvname bs=1M | ssh root@new-server 'dd of=/dev/vgname/lvname bs=1M'

The Partition Table

  • Method 1

You can, if you wish, simply back up the partition table / MBR (sector 0):

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dd if=/dev/sda of=~/sda.sector0 count=1

Then to restore:

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dd if=~/sda.sector0 of=/dev/sda count=1
  • Method 2

Here's another method to save the partition table:

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sfdisk -d /dev/sda > ~/sda.ptbl

And to restore it:

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sfdisk /dev/sda < ~/sda.ptbl

Across the Network

Netcat

On the target machine:

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nc -l -p 1234 | dd of=/dev/sda1 bs=4k

On the source server:

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dd if=/dev/sda1 bs=4k | nc 1234
SSH

To do a dd via SSH:

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dd if=/dev/sda1 | ssh user@destination-srv 'dd of=/dev/sda1'

Cat

Here's the simplest solution for copying an entire disk (partitions, boot sectors...):

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cat /dev/hdx > /dev/hdy

hdx: the source disk
hdy: the destination disk

Partimage

There's the wonderful Part image software which also allows cloning and even over the network into a disk image :-)

Verifying Disk Integrity

Once the disk is cloned, it's best to check the integrity of its data (force a check disk at reboot), for example, in ext3:

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touch /forcefsck

Then restart the machine and at the next boot, it will force the check. After that, you can use it without issues.

CloneZilla

CloneZilla works a bit like Symantec (Norton) Ghost, it allows you to have a server and create copies over the network:
Back Up Restore Hard Drives And Partitions With CloneZilla Live