Backup and Restore Ubuntu Server hard disk or partition  ...

Backup Ubuntu Server hard disk

Backup with compression.

sudo dd if=/dev/sda | bzip2 > /hdd10/backup/image.bz2

Restoring a drive image

bzcat /hdd10/backup/image.bz2 | dd of=/dev/sda

Clone a disk drive to disk drive.

sudo dd if=/dev/sda of=/dev/sdb status=progress

With a larger block size will speed it up.

sudo dd if=/dev/sda of=/dev/sdb bs=1024k

Clone a partition of your Linux disk drive.

dd if=/dev/sda1 of=/dev/sdb1 bs=64K conv=noerror,sync

List Disks on Ubuntu:

sudo lsblk

...