Sunk cost fallacy at work: I need to back up a Drobo with 11 TB of data, before upgrading macOS. I bought a 12 TB hard drive for this purpose, but did not reformat it from exFAT to HFS+ (which would have reduced the block size and made it capable of handling more small files). Now it’s filling up prematurely, but I don’t want to reformat and recopy (because that will take days, and it’s already taken days). 😵