using 'dd' to clone drive

[mahesh]

Hi

I recently ran ' sudo dd if=/dev/sda of=/dev/sdb status=progress to clone my existing drive to an external back up drive

Everything seemed to run with no errors but at end of play I had several directories missing on the back up, including /Home

I have a feeling my error was running dd from live system?? - should I boot from Live CD and run it from there?

Or maybe there's another explanation ...

Any help please