As
@Paul_DS256 mentions, Robocopy comes with W10 and is an excellent tool. You can even schedule it with the windows scheduler.
I am not aware of Cloudberry being able to do disk-to-disk syncs, though it might. It is really a tool for incremental, versioned backups, i.e. those where you can do a point-in-time restore. A real strength is that it is agnostic to media, it works with disks, nas, and most clouds, plus it has an understandable GUI interface.
Goodsync will definitely do syncs as well as backups, including two ways syncs if you choose (almost always a bad idea in my mind). It has great features, just an awful interface and awful documentation.
I like to distinguish between sync'ing two disks (i.e. making one an identical copy of the other) and backing up. To me a true backup must be versioned, you must be able to restore to a point in time. That might not be Webster's definition, but it is absolutely required in today's systems. It is much more likely to need to restore due to failures other than simple media failure of a disk -- software failures, user errors, power outages (or other system failures) causing corruption, etc.
I think people need to run some scenarios to see if they are adequately backed up. None are high likelihood, but they all can happen:
- The latest version of Lightroom wiped out 100 files a day, and you just noticed a week after installing it; can you get them back?
- You had a fire/flood/burglary and your computer system was destroyed with no warning. You can buy a new computer, where are your files?
- As you read this, your computer got infected with nasty malware, and all disk drives currently online were encrypted (including the one you backed up to last night and did not unplug -- or did you?). Can you get your files back?
I'm not asking for answers.... I'm just suggesting you periodically put your black hat on and figure out what can go wrong, and how prepared you are.