MicroSD Card not showing up in SteamOS

[ComputerVirusUD]

Hey all!
I got myself a MicroSD card to expand my storage on my steam deck (SanDisk Extreme 512GB). I formatted it on my laptop to FAT32, then input it into my steam deck and mounted it through desktop mode since it didn't detect it properly the first time I tried it. But it's still not detecting the SD Card from SteamOS.

Dolphin is detecting it and allowing me to view a screenshot I put on there from my laptop to test that the SD card can actually store things and isn't broken, but SteamOS isn't detecting much more than the fact the SD card exists. It won't let me store any games on it.
When I try to format the device through SteamOS, it gives me an error message and it has been pretty useless at describing anything. It's also not detecting the SD Card through the "Storage" section in the settings menu.

Do you have any ideas on what I could do?
Many Thanks for any help you can give.

[PotterheadMando]

All I can tell you is that Micro SD Cards need to be formatted to Ext4, for the card's format, as the SteamOS is based on Linux. So, definitely don't use NTFS, which is a DOS/Windows storage format. It should work after being formatted to Ext4 formatting. I know first-hand from messing around with my own 256GB SanDisk ImageMate Micro SD card. Hope that helps!

[Jâbbérwôkkï]

If you are using windows to format the card so Steam OS will recognize it, use Ex-fat file system will do it. The Deck may want to reformat it after you install it again but at least it will be recognized by it. Sometimes the Deck will have these issues, for either it or something known as user error, in that case using windows {or mac/Linux's) disc management tools to delete it's partition & reformat it as Ex-fat usually will fix it. In that case, if anythings installed on the card you'll have to reinstall it.

[ComputerVirusUD]

Originally posted by ProudEagle96:

All I can tell you is that Micro SD Cards need to be formatted to Ext4, for the card's format, as the SteamOS is based on Linux. So, definitely don't use NTFS, which is a DOS/Windows storage format. It should work after being formatted to Ext4 formatting. I know first-hand from messing around with my own 256GB SanDisk ImageMate Micro SD card. Hope that helps!

Thanks! This worked semi-perfectly.

It just spontaneously started functioning correctly while I formatted the SD card lmao

[PotterheadMando]

Originally posted by ComputerVirusUD:

Originally posted by ProudEagle96:

All I can tell you is that Micro SD Cards need to be formatted to Ext4, for the card's format, as the SteamOS is based on Linux. So, definitely don't use NTFS, which is a DOS/Windows storage format. It should work after being formatted to Ext4 formatting. I know first-hand from messing around with my own 256GB SanDisk ImageMate Micro SD card. Hope that helps!

Thanks! This worked semi-perfectly.

It just spontaneously started functioning correctly while I formatted the SD card lmao

Glad I could help, or kind of at least! Take care!

[[KAMI] RedWyvern]

Adding to this, the reason the SD card has to be formatted to Ext4 (or possibly BTRFS) to work in Game Mode, is that the Proton compatibility layer needs a Linux filesystem as it relies on some specific features it offers.
Because of this you can not share a game library between Windows and Linux, as Proton does not run Windows games installed on NTFS, along with it needing "compatdata" that Windows doesn't need.
SteamOS presumably checks for this in Game Mode, whereas Desktop Mode just lets you mount and use the drive, like a normal Linux system would.

[ComputerVirusUD]

Originally posted by KAMI RedWyvern:

Adding to this, the reason the SD card has to be formatted to Ext4 (or possibly BTRFS) to work in Game Mode, is that the Proton compatibility layer needs a Linux filesystem as it relies on some specific features it offers.
Because of this you can not share a game library between Windows and Linux, as Proton does not run Windows games installed on NTFS, along with it needing "compatdata" that Windows doesn't need.
SteamOS presumably checks for this in Game Mode, whereas Desktop Mode just lets you mount and use the drive, like a normal Linux system would.

Nice.

From what I saw when researching to fix the problem, Ext4 is actually one of the major file systems used in Arch Linux (the Linux distro Desktop Mode is based in).

[[KAMI] RedWyvern]

Originally posted by ComputerVirusUD:

From what I saw when researching to fix the problem, Ext4 is actually one of the major file systems used in Arch Linux (the Linux distro Desktop Mode is based in).

It's actually the major file system used by almost all Linux systems.
The other one I mentioned, BTRFS, is occasionally used for system files as it has benefits there, thought Ext4 is the safe default.
Both SteamOS and the Arch-based distro I run on my desktop use BTRFS for the OS files, but just like SteamOS I have my system set up to use an Ext4 partition for the /home data.

Both of these are Linux-focussed filesystems and work best with it, but while the standards are open Windows does not support them.
Linux does support NTFS, ExFAT, ect., but not to the same degree as Windows.
Example, NEVER repair an NTFS filesystem on Linux if it gets used by Windows too, this is likely to corrupt it.

Circling back to the Deck's SD cards, as I said before this better support by the OS is why Game Mode requires Ext4, given the complexity of games and especially the compatibility layer.

P.S. In case you're curious, I use Garuda Linux on my desktop, but if you wish to try Linux somewhere else (VM, spare machine or drive), start with Linux Mint or Kubuntu.

[ComputerVirusUD]

Originally posted by KAMI RedWyvern:

Originally posted by ComputerVirusUD:

From what I saw when researching to fix the problem, Ext4 is actually one of the major file systems used in Arch Linux (the Linux distro Desktop Mode is based in).

It's actually the major file system used by almost all Linux systems.
The other one I mentioned, BTRFS, is occasionally used for system files as it has benefits there, thought Ext4 is the safe default.
Both SteamOS and the Arch-based distro I run on my desktop use BTRFS for the OS files, but just like SteamOS I have my system set up to use an Ext4 partition for the /home data.

Both of these are Linux-focussed filesystems and work best with it, but while the standards are open Windows does not support them.
Linux does support NTFS, ExFAT, ect., but not to the same degree as Windows.
Example, NEVER repair an NTFS filesystem on Linux if it gets used by Windows too, this is likely to corrupt it.

Circling back to the Deck's SD cards, as I said before this better support by the OS is why Game Mode requires Ext4, given the complexity of games and especially the compatibility layer.

P.S. In case you're curious, I use Garuda Linux on my desktop, but if you wish to try Linux somewhere else (VM, spare machine or drive), start with Linux Mint or Kubuntu.

You learn something new everyday!
Thanks for informing me :)