Backup using dd

Suppose you have a 20GB external hard drive and you want to do a back up quickly, what would you do? Copying the whole thing to a new hard disk is not what you want. You can use dd command in windows, linux or Mac. But here I am gonna talk about doing it in linux only.Ok, so the command goes something like this:



dd if=/dev/sda of=/file1.bin

sda is the hard disk. If you are using IDE hard disk, it should be hda instead of sda. The whole hard disk will be backed up into the file file1.bin. The retrieval of file can be done through FTK Imager which is a freeware and is easy to use.

You can also backup your partitions individually. For example if you want to backup the first partiotion, you can give sda1 or hda1.

If you are not sure whether to use sda or hda, this command  might help you: fdisk -l

You can see the various paritions.

Another use of dd command is to make your data irrecoverable. Even if you delete, the data in your hard disk can be recovered since only the pointer to the data is deleted, some portion of the data might still remain in your HD. Using dd, you can add 0s or 1s to completely destroy the data.