Linux DD Disk Copy, Clone, Backup to image file

Hard Disk Clone

The following command can copy all the content from /dev/sda to /dev/sdb:

dd if=/dev/sda of=/dev/sdb

The following command will create an image file "disk1.img" in your user's directory from /dev/sda:

dd if=/dev/sda of=~/disk1.img

Since you have created an image file, you can compress it with "gzip" or "bzip2":

gzip disk1.img #generates disk1.img.gz or

bzip2 disk1.img #generates disk1.img.bz2

You can save much storage space with compression. But it will take very long time.

Partition Clone

For example, if you want to create an image file from the first partition of /dev/sda, use "dd" like this:

dd if=/dev/sda1 of=~/disk2.img

Also, you can compress the image file:

gzip disk2.img

You can copy a partition to another partition completely. For example:

dd if=/dev/sda1 of=/dev/sdb5


Restoring from an Image File

Restore the whole hard disk from the image file "disk1.img":

dd if=disk1.img of=/dev/sda

Restore the first partition of /dev/sda from the image file "disk2.img":

dd if=disk2.img of=/dev/sda1