Why?

​Even though the Wii U has a built in SD slot, it doesn't support using it as a storage expansion to store Wii U games (unlike it's predecessor). USB pen drives are notoriously unreliable and hard drives are bulky and require extra power or a Y cable, using up multiple ports. Today big reliable SD cards have become cheap. Since a SD is needed anyway for homebrew, it would be nice to use that too as storage for games.
There have been solutions in the past like Loadiine, but this had various problems, the biggest of them performance and is not longer supported by current homebrew environments (Aroma).

SDUSB

​SDUSB solves these problems. It uses a second partition on the SD card, which will be formatted to the Wii Us native file system and therefore run at full speed. The partition will show up as a USB device and can therefore be managed using the built in Data Management in the system settings. SaveMii, WUP Installers etc. all work with this, like it is a USB storage device. Also HAI (VC Wii Titles) work with SDUSB.
SDUSB does all that by patching IOSU (the OS that runs on the ARM processor). It is implemented as a stroopwafel plugin.

If you instead want to partition your USB HDD to use it for Wii U games and other stuff look here: https://gbatemp.net/threads/usb-partition-use-partitioned-usb-hdds-with-the-wii-u.656209/

Prerequisites

​You need two things:

1. a way to launch minute
2. a reliable SD card

For 1. the recommended way is to setup ISFShax, for that we have a guide here: How to set up ISFShax
If you don't want to commit to installing ISFShax yet you can skip the "Installing ISFShax" step in the ISFShax setup guide and instead run it manually through the chosen exploit on every reboot.
Instead if ISFShax you can also use defuse, in case you have that already.

For 2. It is highly recommended that you use an Endurance branded SD card from a reputable brand. Since your save games will also be saved there, you rather want to spend $5 more then to lose all your save games because your cheapo sd card died. Also be aware of fakes, even on Amazon you can get fake SD cards...
The speed of the SD card isn't too important, as the Wii U is limited to 25MB/s (same as the internal memory) anyway. Every somewhat recent SD card should be able to get that speed. Choose Reliability > Access Time > Throughput.

Setup

​

Partitioning the SD card​

On Windows you need to use a third party tool like Minitool Partition Wizard or Easeus, on Linux you can use gparted.
You need to have two primary partitions on the card:

1. FAT32 - (in gparted set lba flag). This is what the PC will see and all your homebrew goes (you should already have this)
2. NTFS - This partition will be the "USB", you use to store the Wii U games on (don't assign a drive letter)

Shrink the existing FAT32 partition to make room and then create the primary NTFS partition after it. It's recommended to align the Partitions on 64MiB boundaries and use a multiple of 64MiB for the size. NTFS won't be the file system the Wii U will be using, it is just there to tell SDUSB which partition to use (it will pick the first NTFS one). The Wii U will later format it with it's own file system.

​

Installing the Plugin​

Get the latest wafel_sd_usb.ipx from here: https://github.com/jan-hofmeier/wafel_sd_usb/releases and place it in your ios_plugins folder. That is either wiiu/ios_plugins on the SD card or /sys/hax/ios_plugins on the slc. For slc you have to rename it to something shorter like sdusb.ipx

Using SDUSB

​If you now boot boot back up, the Partition shows up as a USB device, which needs to be formatted and can then be used as usual. After formatting the SDUSB, you can also connect an existing USB storage and copy stuff over.

Known Problems

​

• GC VC Injectes don't work when installed to the SDUSB (they still work from Internal Memory)

 

[EmergencyStrike]

Hey, I was unable to get SDUSB to work and I'm not sure what I did incorrectly. I used a completely new 64GB SD card in order to homebrew the Wii U and then installed ISFShax on it. I used the EaseUS partition master to partition my SD card to NTFS and then used Disk Management to remove the drive letter. For some reason, the Wii U can't see the NTFS part and it won't let me format it in order to use it. Any idea what might have went wrong?

Here's what my partitioned SD card looks like below.

 

[SDIO]

You made it a logical partition, it needs to be primary

 

[EmergencyStrike]

Does that mean the E: needs to be the logical part instead? (Just double checking)

 

[chrisis685]

Does that mean the E: needs to be the logical part instead? (Just double checking)

Both partitions need to be primary, no logical partition at all (I don't use EaseUS but I assume there is a function there as in all similar tools to partition the SD there that way)

 

[EmergencyStrike]

Looks like it worked! Thanks for the hard work you put into this .

 

[mrmagicm]

Hi SDIO! I have a question because I am a multi wiiU user, I have 4 wiiU, what happen if I have 1 Sd card and 4 wiiu.
What are the operation that I have to do multiple times and the 4 wiiu and the operation I must do on the only one SD card? Do I have to have a SD card for each WiiU to be able to use this, and can I use the one SD on all WIIU?

 

[SDIO]

You can swap one SD card between Wii Us, you would just need to run the ISFShax installer on each Wii U. But the tickets are on the SLC, so if you installed a game on one Wii U, it won't wrk on another one, if it wasn't installed there before.

 

[mrmagicm]

ok so what happen if you load it? Just dark screen? Not dangerous?

 

[SDIO]

It should give you the message that the NNID used to buy it was deleted or something like that

 

[tmnr1992]

You can swap one SD card between Wii Us, you would just need to run the ISFShax installer on each Wii U. But the tickets are on the SLC, so if you installed a game on one Wii U, it won't wrk on another one, if it wasn't installed there before.

If I'm understanding correctly this ignores the console's HDD encryption, allowing us to use the same SD card (detected as a HDD) on any Wii U with ISFShax and the game tickets installed, is that right?

If so does that also apply to your other program USB Partition?

 

[SDIO]

If I'm understanding correctly this ignores the console's HDD encryption, allowing us to use the same SD card (detected as a HDD) on any Wii U with ISFShax and the game tickets installed, is that right?

Yes

If so does that also apply to your other program USB Partition?

No. For SDUSB I had to disable the encryption, as it wouldn't work there correctly (would show up as unformatted after every restart). I tried to disable the encryption for the read USB HDD with the USB Partition plugin, but it didn't work correctly after a restart and I didnÄt investigate that further.

 

[OldWiiGamer]

Hi,

I see Sandisk has both "High Endurance" and "Max Endurance" SD cards. The Max ones seem to be very expensive in my country and the "high" ones are expensive but still doable.

Is it okay to just get a "high" endurance one?

 

[SenorStrix]

Does this work with Aroma? I can't find the ios_plugins folder the guide is talking about.

 

[SDIO]

You have to create it

 

[OminouS]

Hello,
A few days back I modded my WiiU and installed SDUSB on SandDisk High Endurance 512 GB. Got like ~286 GB for SDUSB and 190 GB for FAT32 (vWii). I installed some games through WUP GX Installer and everything works fine. But when I try to install some large games (like Zelda: BOTW or even sometimes 1.6 GB game) WUP GX stops randomly installing games at x% and I have to force shutting down the console. When I try 2nd time, it usually installs the same game correctly. When I installed a lot of small games up to 1GB with updates (setting up the queue) nothing stopped. At last I switched to nusspli lite and it's the same. The larger the game, the harder to install it even at 2nd attempt. Something is wrong. Any ideas? Another WUP installer, but are there any left?

#edit
I guess, 2nd time installing Zelda BOTW on nusspli stopped exactly at 74% like previously. Maybe this WUP is corrupted or something. But when it comes to other games, I managed installing them at 2nd attempt with the same files...
#edit 2
I installed another large game ~10 GB first attempt (using nusspli), then decided to get Zelda from another source. It stopped at 65% this time. Weird.. This is so random, what may be wrong?
#edit 3
some specific games just can't install and stops usually at 60-80%. some are installable at first try. SD card is brand new and works flawlessly. WUP files can't be corrupted I think, I used USBHelper on windows because many people claim it's the best downloader.

 

[devlman127]

I haven't had any problems with USB pen drives (other than the known GCN inject problems) but this could be nice to free up the rear USB slots for a gamecube controller adapter while leaving the front of the console clean. Still, I wonder if it's worth the risk using the relatively new ISFSHax...

 

[fate6]

Hello,
A few days back I modded my WiiU and installed SDUSB on SandDisk High Endurance 512 GB. Got like ~286 GB for SDUSB and 190 GB for FAT32 (vWii). I installed some games through WUP GX Installer and everything works fine. But when I try to install some large games (like Zelda: BOTW or even sometimes 1.6 GB game) WUP GX stops randomly installing games at x% and I have to force shutting down the console. When I try 2nd time, it usually installs the same game correctly. When I installed a lot of small games up to 1GB with updates (setting up the queue) nothing stopped. At last I switched to nusspli lite and it's the same. The larger the game, the harder to install it even at 2nd attempt. Something is wrong. Any ideas? Another WUP installer, but are there any left?

#edit
I guess, 2nd time installing Zelda BOTW on nusspli stopped exactly at 74% like previously. Maybe this WUP is corrupted or something. But when it comes to other games, I managed installing them at 2nd attempt with the same files...
#edit 2
I installed another large game ~10 GB first attempt (using nusspli), then decided to get Zelda from another source. It stopped at 65% this time. Weird.. This is so random, what may be wrong?
#edit 3
some specific games just can't install and stops usually at 60-80%. some are installable at first try. SD card is brand new and works flawlessly. WUP files can't be corrupted I think, I used USBHelper on windows because many people claim it's the best downloader.

Anecdotal but I have used NUSspli to install very large games like Watch_Dogs and have had no such issues, where i have seen similar issues was on my Steam Deck when the SD card was overheating.

 

[V10lator]

I used USBHelper

USB Helper is known to sometimes fail on large downloads so that might be your issue. Try Wii U Downloader or NUSspli (not Lite) instead.

many people claim it's the best downloader.

It really isn't.

 

[OminouS]

Unfortunately I didn't manage to fully solve this problem. Things I did:
- backup of whole FAT32 partition, format it and restore
- downloading games alternately using Wii U Downloader/USB Helper
- installing games alternately through WUP Installer GX/NUSspli (standard this time, not Lite)

For example I installed Xenoblade Chronicles X (big game, 20 GB), then its update at first attempt. DLC (10 GB) cannot be installed no matter what - just now it failed for the 6th time at 94%. Wii Party U was succesfully installed, hmm, maybe at 5th time? Zelda (10GB) at 4th time, update (3GB) at 3th, DLC (2GB) at 1st etc.. I thought that if the installation passess 80+% the game is always installed. Whenever stuck happens, it's at 40-80%. But now Xenoblade DLC failed at the end. When stuck happens, in NUSspli it shows 0B/S and I have to shut down the console. After that I clean WiiU partition in data management in native settings (communication about deleting unnecessary content), but I can see there is no space occupied after failed installation, so installers delete failed content automatically I guess.
Even I checked, and directly after installation of the game, when I eject SD card, it's cold. No issues with it. What causes stopping installation and it isn't corrupted games? If them can be installed, using the same file at 4th time for example, then the game launches flawlessly, files must be okay. Console losing connection with SD card, not enough power?

I think it may be software problem. WUP installer stops installing early, up to 40%, while NUSspli stays longer and can finally install the title. But not Xenoblade DLC. Maybe I should get nusspli or WUP Inst. older version?

 

[Joriaan]

For example I installed Xenoblade Chronicles X (big game, 20 GB), then its update at first attempt. DLC (10 GB) cannot be installed no matter what - just now it failed for the 6th time at 94%. Wii Party U was succesfully installed, hmm, maybe at 5th time? Zelda (10GB) at 4th time, update (3GB) at 3th, DLC (2GB) at 1st etc.. I thought that if the installation passess 80+% the game is always installed. Whenever stuck happens, it's at 40-80%. But now Xenoblade DLC failed at the end. When stuck happens, in NUSspli it shows 0B/S and I have to shut down the console.

I've had the exact same issue you described a few weeks back, and from what I can tell it's part random luck, part whatever downloader you're using not fully downloading all the files, and part not all files being written to the SD card right. Only way to is to keep redownloading the same game and keep trying to install it again, and I've found that using the Copy To SD function by Wii U USB Helper getting good results when it comes to getting everything onto the SD card right - try that from now on.

As for XCX's DLC: don't worry about it, it's already included in the US/PAL versions so you don't need it.