Give CCC a try, you won't believe how easy it is to "clone a drive".
You can also clone partitions of a drive, to other drives and/or partitions.
The initial clone will take a while to complete, as it copies EVERYTHING on your source drive.
Afterwards, "incremental" backups go much faster, because only changed files are copied.
Also -- if you do a backup clone of your internal (boot) drive, I suggest you do a "test boot" after the clone is finished. To do this:
- Leave the backup drive connected and powered on
- Restart
- As soon as you hear the startup sound, hold down the option key and KEEP HOLDING IT DOWN
- In a few moments, the startup manager will appear
- Use the arrow key to select the backup drive, then hit enter/return
- The Mac should boot from the backup
Note: doing a "switch-boot" as above does not change the setting in the "startup disk" preference pane. If you reboot again, the Mac should boot from the internal drive as before.