SCCM Switch Toolbox now formats Switch SD cards in a four-stage workflow: Select Drive, Review, Configure, and Confirm. Preserve mode keeps your HOS files and any existing partitions you want to hold onto, shifting their data around the card as needed so you don’t have to restore from a backup afterwards. If you’d rather wipe everything and start clean, you can do that too.
This guide walks through the full format process from start to finish.
Warning: Even with Preserve mode, you should always have a backup before formatting. If anything goes wrong mid-process (power loss, cable disconnect, bad SD card sector), the data being shifted around can be lost. Make a backup first using the Backup tab in SCCM Switch Toolbox.
What You’ll Need
- The SD card you want to format
- A computer with SCCM Switch Toolbox
- An SD card reader (built-in or USB)
- A current backup of anything on the card
What HOS Data and Preserve Mode Actually Mean
A couple of terms come up throughout the workflow that are worth understanding before you start:
- HOS data is everything in the FAT32 partition that the Switch reads. That includes Atmosphere, homebrew apps, payloads, tools, configs, and your file-based EmuMMC if you have one.
- Preserve mode keeps your HOS files and any existing partitions you check off. The formatter resizes the card layout and moves the kept data into the new positions. If your HOS partition has a lot in it, expect the shift to take a while.
- Wipe mode kicks in when you uncheck “Preserve HOS data.” Everything on the card is erased and rebuilt from scratch.
Formatting Your SD Card
1. Open the Format Tab and Select Your Drive
Launch SCCM Switch Toolbox and click Format in the left sidebar. The first stage is Select Drive. The red banner at the bottom is a reminder that what happens to your data depends on choices you’ll make on the next two pages, so a backup is still a good idea either way.
Click Select Drive to open the picker. Only removable drives show up here. SD cards that have already been formatted for the Switch are tagged with [SWITCH] so they’re easy to spot. Pick the right one and click Next.
2. Review What’s on the Card and Pick What to Preserve
The Review stage shows the current layout of your card and gives you a few decisions to make:
- Preserve HOS data keeps the contents of the FAT32 partition (your Atmosphere install, homebrew, payloads, tools, and a file-based EmuMMC if you have one). Leave it checked to keep your files. Uncheck it if you want a clean wipe.
- Keep existing partitions lists every non-HOS partition the toolbox detected (EmuMMC, Linux, Android). Check the ones you want to hang on to. Anything unchecked gets erased and its space rolls back into HOS.
Anything you check stays on the card with its contents intact. The formatter will shift the data around as needed to fit the new layout, so if a kept partition is large, this stage of the format takes longer.
Click Next when you’re happy with your selections.
3. Configure New Partitions
The Configure stage is where you add anything new to the layout. Pick your Switch model, check the partitions you want to add, and set their sizes with the sliders. The Proposed Layout preview at the bottom updates live so you can see how the card is going to be carved up.
- Switch Model matters when you’re creating an EmuMMC partition. It sets the correct EmuMMC size for your console.
- Add emuMMC (RAW) creates a raw partition for a partition-based EmuMMC.
- Add Linux ext4 creates a Linux root partition. Pick the build label from the dropdown.
- Add Android (userdata size) creates an Android userdata partition. Pick the partition type from the dropdown.
HOS Data soaks up whatever space is left over. If you add Linux or Android, the HOS partition shrinks to make room. If you skip them and don’t keep any from the previous stage, that space goes straight back into HOS.
Note: Adding an EmuMMC partition to a card that already has data on it isn’t supported right now. If you want to add one and you don’t already have an existing EmuMMC partition to keep, you’ll need to do a fresh format (uncheck Preserve HOS data on the Review stage). This is a current limitation and will be addressed in a future release.
Note: Linux builds other than Ubuntu Noble and Android partition types other than Dynamic are experimental and haven’t been fully tested. They may work, but if you run into issues with one of these builds, please submit a bug report so it can get tracked down.
When the layout looks right, click Next.
4. Confirm and Format
The Confirm stage is the last checkpoint before anything is written. You get a side-by-side of the current layout and the after-format layout, plus a Change Summary spelling out what’s being preserved, kept, added, and removed. Read through it carefully.
If everything checks out, click Format Card. A confirmation dialog pops up summarizing exactly what’s about to happen, including the partitions being added in MiB. Click Yes to start the format.
Important: The formatter mounts and unmounts the SD card several times during the process. Windows may pop up warnings that the drive is inaccessible, needs to be formatted, or appears corrupt. These are expected. Just close them and let the toolbox finish its work. Do not click any “Format disk” prompts that Windows throws at you.
5. Wait for the Format to Finish
A progress window opens showing the current operation and an overall percentage. If you’re using Preserve mode with a lot of HOS files or kept partitions, this can run for a while because data is being shifted around the card. Let it run, do not unplug the card, and don’t touch any Windows prompts that appear.
When you see Complete at the top of the window, the format is done. Click Close to dismiss the dialog.
Tips
- Always back up first. Preserve mode is reliable but not magic. A power blip mid-format can still cost you data that’s being moved around. The toolbox’s Backup tab packs HOS, EmuMMC, Linux, and Android into one
.sccmbakfile in a single workflow. - Preserve mode rewards a tidy HOS partition. The more data you’re asking the formatter to shift, the longer the format takes. A few GB of homebrew is fast. A nearly full FAT32 partition with a file-based EmuMMC is going to sit there for a while.
- Match the Switch Model to your console. Picking the wrong model when you’re creating an EmuMMC can leave you with one that doesn’t fit. Double check before you confirm.
- Adding an EmuMMC needs a fresh format. If you don’t have an existing EmuMMC to keep and you want to add one, you’ll have to wipe the card. This is a current limitation.
- Stick with tested builds. Ubuntu Noble for Linux and Dynamic for Android are the known-good combinations. Other selections work in some cases but aren’t guaranteed yet.
- Ignore Windows popups during the format. The drive will appear and disappear several times. Closing the warnings is the right move. Do not let Windows format anything for you.
- Eject and reinsert when done. A clean re-mount avoids weird behavior when you start writing files to the new partitions.
Related Guides
- How to Back Up Your SD Card with SCCM Switch Toolbox
- How to Back Up and Restore Your EmuMMC (Partition-Based)
- What’s Installed on Your Modded Switch
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