[CentOS] "WARNING: fdisk GPT support is currently new"

Sun Oct 7 14:04:34 UTC 2018
Warren Young <warren at etr-usa.com>

On Oct 7, 2018, at 4:49 AM, Nicolas Kovacs <info at microlinux.fr> wrote:
> * use traditional fdisk with DOS-MBR style partitioning on systems that
> supported it

Unless you only need 4 or fewer partitions and are using 2TB or smaller disks, I can’t see any good reason to use MBR on desktop, laptop, or server systems these days.

(MBR does still have some well-justified use in the embedded world, removable media, etc.)

> As far as I can tell, the CentOS installer is doing something similar,
> but "automagically". Please correct me if I'm wrong.

I believe the primary criteria the CentOS installer uses is that it checks whether it was booted via EFI or BIOS.  If EFI, it assumes it must use GPT partitioning to get a bootable system.

Obviously if you’re installing onto a > 2TB disk or drive array, it also uses GPT.

You can tell which case you’ve fallen into by doing manual partitioning in the installer and then seeing whether the installer offers you the option of creating a “biosboot” partition or /boot/efi.