Is it worth having a clone disk?

[Mike Watterson]

I note you're leaving your backup drive connected to your PC at all times. Not a good idea. If something goes horribly wrong (for example some types of malware) your backup files could easily be lost. You can also accidentally overwrite something on it that you didn't intend.

He's totally correct. It's just an extra drive it if always connected, not a backup. I used to have to explain that RAID didn't mean no backups were needed. Even without malware an online drive can be damaged by HW failure or deleted by OS bug or user error.

I've seen tops blow off chips on an HDD controller when a PSU failed. In that case I was able to recover the user's data by swapping a controller off a same model drive. That's not likely to work with newer drives.

There is also time delayed ransomeware-malware, so for critical information you need separate archived backups. Also Internet (Cloud) is better for publishing and sharing than backups.