On Sat, May 14, 2022 at 1:52 PM Peter Boy <pboy(a)uni-bremen.de> wrote:
Last meeting we discussed whether we should change to GPT as default partitioning. Now
some of our members have submitted a change proposal to make GPT the default partitioning
for new installations. I think this is actually long overdue, yet better communication
among us would actually be nice as well.
https://fedoraproject.org/wiki/Changes/GPTforBIOSbyDefault
I don’t know if there is a potential problem. Some time ago, if I remember correctly it
was Neil who wrote in a discussion about storage that a software RAID is no longer
possible, because - so my memory - the biosboot partition is not replicable over multiple
disks. So if the previous boot disk fails, you can't just boot from another disk.
Last time I checked this particular configuration of /boot on multiple
drives in e.g. a raid1,10,5,6 - on BIOS firmware only, Anaconda issues
the grub2-install command pointing at all the member drives making up
/boot. Whether MBR or GPT, the proper GRUB core.img is installed on
each. So any of them will get you to at least a grub rescue prompt. Of
course it requires the minimum number of disks for GRUB's md driver to
assemble the member drives so it can read /boot to find additional
grub modules and grub.cfg and the kernel and initramfs.
The problem still remains unsolved though for UEFI. Upstream GRUB
suggest sequentially mounting each ESP on each drive, and issuing
grub-install. We don't use grub-install (or grub2-install in Fedora
land) for UEFI at all though, because the grubx64.efi is built in the
Fedora build system and signed for UEFI Secure Boot. Even if the
installer were to mount each ESP in turn, copying the bootloader
configuration files to each one, and then adding the proper entries in
NVRAM for each one to act as fallbacks - the problem is they all get
out of sync as kernels and bootloader updates happen. There is an idea
how to handle this in Fedora CoreOS, a project called bootupd. But
this particular work isn't finished yet, specifically for the
raid/multiple boot disks use case.
https://github.com/coreos/bootupd
--
Chris Murphy