I regularly connect various drives to my system temporarily, just to be able to shuffle files around onto other volumes. The problem is that when I have these drives connected, Time Machine will stupidly try to back them up. This is a problem when I'm connecting 8TB drives and my Time Machine drive is only 2TB. I don't want or need these drives backed up. In fact, I only really want to back up two drives and nothing else. But no matter how many times I drag the drives into the excluded drives list in Time Machine preferences, they eventually show up again after being disconnected and reconnected a few times. Does anybody know if there's any way to tell Time Machine to stop being so eager to back everything up, and just stick to backing up the two volumes I tell it to?