A proposal raised for Fedora 43 would end support for allowing UEFI installations on MBR-partitioned disks for x86_64 systems in the Anaconda installer. This would enforce a requirement on using GPT partition tables for all UEFI-based Fedora installations in the x86 world.

Most users running on a modern UEFI system should already be using GPT partition tables but for some exotic system configurations, Fedora Linux is looking to remove that ability beginning with Fedora 43's release later this year.

The change proposal explains:

"Anaconda will no longer support installing in UEFI mode on MBR-partitioned disks for X886. While the UEFI specification technically permits booting from MBR (msdos) disks, in practice this configuration is unreliable, inconsistently supported by firmware, and not tested in Fedora.

Fedora’s GRUB2 bootloader documentation already assumes the use of a GPT partition table for UEFI installations.

By enforcing GPT in UEFI mode, Anaconda will provide a more robust installation experience by avoiding bootloader crashes (e.g., efibootmgr failures).

Support for UEFI on MBR was originally added in blivet#764 to accommodate cloud image use cases, such as AWS, which at the time did not support UEFI booting on GPT disks. These constraints no longer apply to modern cloud platforms, making MBR-based UEFI setups unnecessary for current Fedora deployments.

This change only applies to x86 systems booted in UEFI mode. Other architectures (such as ARM and RISC-V) are not affected, as their UEFI implementations may still depend on MBR partitioning."

This change aims to enhance the reliability of Fedora with UEFI and reduce the support burden by having one less installation route to test. More details for those interested via the [1]Fedora Wiki . This proposal still needs to be voted on by FESCo.



[1] https://fedoraproject.org/wiki/Changes/Anaconda_Drop_Support_UEFI_on_MBR