Anaconda as far as I can tell ties together the concept of an abstract "bios" booted system with the need to use MBR partitioning. I suspect it does this due to inheritance from x86.

But at least ppc64le and s390x support booting fine with GPT partition tables...ok well there's a lot of ways to boot ppc64le and I am not 100% sure all support GPT but I'd be pretty suprised if they didn't.

s390x with zipl reportedly works fine with GPT by default.

We have been shipping GPT consistently across all 4 architectures with Fedora CoreOS derivatives since its creation, and I would like to continue this with Fedora bootc derivatives including RHEL Image Mode.

Let's change Anaconda to default to GPT at least by RHEL10.

xref:

• https://github.com/containers/bootc/issues/742
• https://github.com/osbuild/bootc-image-builder/pull/497#discussion_r1681487157