If you want to clone logical partitions or entire HDDs blockwise the linux tool dd comes often into play. This is perfect, but after hours of consumed CPU time the question arise: “How to detect the progress of dd?”
dd responses to the USR1 kill signal with a statistic output without interrupting its operation. Therefore, find the <PID> of your dd tasks, e.g.
ps aux | grep 'dd'
watch -n 30 kill -USR1 <PID>