How do I prep a 256gb micro SD card for pi 3 B?

[VictimRLSH]

I know these can be used, can I just burn the retropie image to the card and then expand the filesystem, or do I have to use Guiformat beforehand?

[mitu]

You can just write the image to the card, it's enough. It might take a bit of time on first boot to expand the filesystem, so have a bit of patience on that first start.

[tpo1990]

Try @mitu solution first and if it fails, download NOOBS from Raspberry Pi Foundation or PINN from sourceforge and use a partition tool such MiniTool Partition Wizard Free or EaseUS Partition Master free to create a small fat32 partition with like 8 gb of size from the micro sd card.

With this approach you should be able to boot into NOOBS or PINN and install RetroPie from there. NOOBS or PINN should automatically create an ext partition and use all the free space of the micro sd card on first boot.

[VictimRLSH]

I might try imaging and re-writing my current image onto the new card first and seeing if it will expand into the larger space. I have Exagear on there and Eltechs went bust. I hear the licensing server still works, so will give that a shot.

[VictimRLSH]

This worked, but was not automatic, I had to go into raspi-config advanced options and manually select Expand Filesystem.

[mitu]

@VictimRLSH That was to be expected - the expansion of the filesystem is only done on the first boot of an Raspbian/RetroPie system. If you cloned an existing system, you need to trigger it manually using raspi-config.

[VictimRLSH]

I might use a fresh install anyway and keep the old 32gb card around if I need to run x86 apps. I'm making a much more compact build of my controller mounted build and will lose the USB stick to save some space.

UPDATE: Exagear is now a brick, the licensing server is offline too. New card works fine and all space is available.

[tpo1990]

@VictimRLSH Good work. I did not know that you were trying to use a cloned existing system. I'm glad that you got it working now.