Redundancy for EFI System Partition: what do people do in 2020?

[Andy Smith <andy@strugglers.net>]

Hello,

More of my adventures in EFI land.

Machines that boot by EFI need an EFI System Partition. I'm used
to using software RAID everywhere and providing redundancy for
everything. It seems that the designers of EFI didn't think about
that one.

    https://www.tinkerfairy.net/efi-raid.txt
    https://www.claudiokuenzler.com/blog/696/uefi-efi-boot-does-not-like-software-raid-system-partition-grub-error-17
    https://unix.stackexchange.com/questions/265368/why-is-uefi-firmware-unable-to-access-a-software-raid-1-boot-efi-partition

So, those of you who boot by EFI and use software RAID, how do you
choose to provide redundancy for your ESP any why did you make that
choice?

I understand the main choices are:

a) Don't provide redundancy.

   There's only one ESP. If the device it's on dies you can recreate
   it with a live environment such as the rescue mode of the
   installer.

b) Put the ESP in a v1.0 mdraid level 1.

   As the RAID metadata is at the end, it appears to the firmware
   like a normal filesystem for read purposes. Updating it from
   within the OS writes to both copies as it's a RAID-1.

   Has the risk that if the firmware writes to it (which apparently
   it sometimes does), it will corrupt the RAID.

c) Manually sync the ESP to another partition which can be used if
   the first device dies.

   An identical partition can be created on the second device and an
   arrangement made to copy the real ESP to the secondary partition
   every time grub-install would be run.

   You would have to be sure that this is as automated and foolproof
   as possible, to avoid being lulled into a false sense of security
   and then have a problem at the worst time.

d) Something else?

Cheers,
Andy