Backing up or imaging the whole drive

If you ever find yourself wanting to backup / image the entire drive because you're going to play around with or install questionable software , or if you are trying to dual boot Microsoft Windows and Linux etc. or anything else that jeopardizes your precious data then it would be wise to make an image of your drive. Boot from a Linux bootable USB and then use the dd command from terminal to make a copy of your drive.

# Backup
dd if=/dev/sda of=mydrive.img bs=512 count=1

where /dev/sda is your disk. You can find your root or boot drive/partition by running df -h. If you have an NVMe drive like the newer systems then you'd see something like /dev/nvme0n1. The command above will save your drive to a file called mydrive.img in your current working directory.

To restore, again boot from a bootable Linux usb and run the following. It assumes that mydrive.img exists in your current directory.

# Restore
dd if=mydrive.img of=/dev/sda 

Pro Tip: mount another external USB drive or mount a network drive to save the mydrive.img because chances are that your Linux bootable drive is probably not big enough to store image of your entire disk.