Is it supported to switch the BIOS boot to UEFI boot on preinstalled Red Hat Enterprise Linux machine?

Environment

• Red Hat Enterprise Linux 6
• Red Hat Enterprise Linux 7
• Red Hat Enterprise Linux 8
• Red Hat Enterprise Linux 9
• Red Hat Enterprise Linux 10

Issue

• The system is installed with BIOS Boot i.e. Legacy Boot enabled, now it's required to make it UEFI Boot, is it possible without reinstalling the server?

Resolution

• It is technically possible to convert, but there is no supported way to do it yet.
• The BIOS boot doesn't contain /boot/efi partition with efi filesystem in it, and the Red Hat Enterprise Linux bootloader is installed on first sector MBR whereas in UEFI, this partition exists and grub in installed on first sector of /boot partition, so lots of filesystem changes which can't be achieved to match once the system is installed.
• It's required to have a clean system reinstall to make it UEFI boot.
• Switch from UEFI boot to BIOS boot is also not supported.

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