X86_64, sysupgrade 2GB root-parition custom firmware image

Hello,

So I have 19.07.3 stable firmware on a x86_64 machine right now.
The /root partition is 256MB.
I have a 64GB SSD in the machine.

Im planning on using 19.07.4 imagebuilder and selecting the packages i already have on 19.07.3, and then sysupgrade with keep settings.

My question is.
If my /root is 256MB right now, and i have almost 64GB not allocated, could i define in the 19.07.4 custom image im creating, that the /root should be for example 2GB, and it will work when doing sysupgrade?

I have 8GB RAM so uploading the new firmware to /tmp should not be a problem, however i dont know what will happend when i sysupgrade 256MB -> 2GB?

Thanks

I'm not sure how you'd do it with imagebuilder, but if you're compiling an image from source you can set a root filesystem partition size. The created image will be substantially smaller than the final partition size (my RPi4 image with a 4GB root partition is only 31MB) so uploading and sysupgrading won't be an issue.

Yes you are correct, im doing it from source, git clone etc.
When i set 2048MB as /root in make menuconfig, the img before zipped is 2GB