Backing up multiple drives to one external HD using Time Machine
I have an external 4 TB HD and wanted to back up: 2 external 1TB HDs and the internal HD for my iMac. I did this the other day and confirmed that the files were for my 2 external HDs and one internal HD. Then, today, I went to back up only my internal HD again and noticed that the files for my two externals had been deleted. They were deleted despite the fact that the 4 TB backup drive should have had plenty of space (ie, Time Machine shouldn't have been deleting files to make room). Can I back up multiple drives like I'm trying to do onto one, larger HD? Now that I look at it, this should be in the Big Sur forum, but I'm unclear on how to change it.