I'm the partner mentioned in this post.
For context cuz I feel like my questions will sound stupid without it—I have already in the past run backups off a hard drive in VWii using USBloader but I had a stroke since then and while I remember p much everything else, I couldn't remember jacksh*t about this other than maybe a USB conflict existed. I couldn't even remember why I used to have a hdd connected to my wii u other than it maybe could of been related to that, so I thank y'all a ton for these answers. Super helpful.
But I do have a few more questions. I remember now that instead of a Y cable, I used a usb hub. I only did because a guy at the hardware store told me I shouldn't use a Y cables for reasons similar to what Shadow#1 mentioned. He gave me a usb hub and told me to use it instead, but idk why. Does that safely generate power? Would it be a viable alternative to an externally powered hdd if I, for whatever reason, would want an alternative to that? Just asking to keep my options open.
Last thing and I feel like an ass asking this but what is an externally powered hdd? like I know what that is and have seen it before but I just cannot for the life of me comprehend how to search for that on Amazon. I struggle to tell apart listings from more common plug and play ones. It's a stroke thing so I apologize for my stupidity on that