Nintendo life has posted quite a good guide on using External Storage on the Wii U, here are some key points:
First things first: you’ll need to figure out what kind of USB storage to buy, or if a drive you already own will do the trick. For a USB drive to work with the Wii U, it needs to:
- Be powered by an external power adaptor (i.e., requires its own power outlet)
- Draw power from USB by using a Y-cable, taking up two USB ports on the Wii U
- Have a total capacity of two terabytes (2TB) or less
The current 2TB size limit is a restriction that Nintendo plans to remove in the future. However, while this proposed update will allow larger HDDs to be recognized by the system, the maximum available storage will still be capped at 2TB, and any additional space on the drive past that limit will be unavailable to the Wii U.
Note that USB thumb drives and flash storage are not recommended as external storage on the Wii U; Nintendo has explained that because flash storage has a maximum number of reads/writes, it’s unsuitable for the type of continuous data access needed to run games.
Nintendo maintains a (currently very short) list of specific USB hard-disc drives known to be compatible with the Wii U at this link, though it’s far from exhaustive – any drive that fits the basic specifications (external adaptor or Y-cable power supply, 2TB or less) should work. Our tests were performed on a 500GB Iomega HDD powered by Y-cable not listed on Nintendo’s site, and we encountered no problems.
Once you’ve got hold of your USB drive, it’s a simple process connecting it to your Wii U. First though, if you’re going to be using a USB drive you already owned, make sure you back-up everything you need off of it before you begin. You’ll need to format it to use it with the Wii U, and that process erases any and all data on the drive. It also makes it inaccessible to computers and other devices, so you’ll need to dedicate a HDD entirely to the Wii U.
Step 1: Make sure your Wii U is turned off.
Step : Plug the HDD into the USB port(s) on the back of the Wii U.
Step 3: If you’re using a drive with external power, make sure it’s plugged into its own power outlet. If you’re using a USB-powered drive, make sure you’re using a Y-cable and both USB ports on the back of the Wii U.
Step 4: Turn on your console. After a short wait, you should be prompted that you’ll need to format your USB device to use it with the Wii U.
Step 5: Select “Format” – remember, this will erase any data currently on the hard drive, and once you format a drive for the Wii U, you won’t be able to use it on a PC or Mac without re-formatting it.
Step 6: Once the formatting process is complete, you’ll be returned to the Wii U Menu, and a blue icon in the lower left-hand corner will indicate that your HDD is set-up and ready for use!
To read the complete helpful guide, visit the source:
Guide: Using USB Storage with the Wii U