How to back up an external disk drive?
How to back up an external disk?
How to back up an external disk?
As long as it is formatted for a Mac (Mac OS Extended, APFS), and it is not in the Time Machine exclusion list, then Time Machine will back it up.
Exclude files from a Time Machine backup on Mac - Apple Support
As long as it is formatted for a Mac (Mac OS Extended, APFS), and it is not in the Time Machine exclusion list, then Time Machine will back it up.
Exclude files from a Time Machine backup on Mac - Apple Support
Thanks. That eases my mind about backups as I have critical files on an external disk.
How to back up an external disk drive?