Isn't the point of the union mount to let you write files too?Yes that should work but when you have a Savestate or a Highscore will it not be saved when i use the PND. Its readonly then
Oh I see. That sucks. Can't qemu somehow be modified to work with read-only images with diff saves? Probably too much work...That is a problem with the qemu way of executing things.
In the pnd is a big hdd image file. The games are installed into that. If you run it from the pnd it cannot write to the file and you cannot save etc..
Can't you make it as if the games are on a CD-ROM at D: and have an initially empty drive at C: where the games can put their savefiles?
That would already be an improvement, but you would still lose the squashfs compression.Only thing I could think of is downloading the hdd image from the server directly to appdata on first start so you don't need to provide it in the pnd itself.