Comment 4 for bug 561573

I don't consider this a bug and will not fix it. Aligning to cylinder boundaries is a performance disadvantage on modern hardware, and systems that still need it are very rare. You can use 'fdisk -c' to switch off DOS-compatible mode and avoid the warning.

If you need to use cylinder alignment, you can boot the installer with the partman/alignment=cylinder option. However, I do not recommend this simply to avoid a warning from fdisk; you should only do it if there's a real problem.