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