Re: Transferring an existing system from non-RAID disks to RAID1 disks in the same computer

On 1/15/23 04:20, Wols Lists wrote:

IF YOU CAN GUARANTEE that /boot/efi is only ever modified inside linux, 
then raid it. Why not? Personally, I'm not sure that guarantee holds.

Your EFI bios can write to these partitions, too, under operator control.

If you do raid it, then you MUST use the 1.0 superblock, otherwise it 
will be inaccessible outside of linux. Seeing as the system needs it 
before linux boots, that's your classic catch-22.

I recommend *not* using any raid on your EFI partitions.  Make them all 
separate, so your BIOS can tell that they are distinct filesystems (raid 
would duplicate the FS UUID/label/CRC).

When separate, you can use efibootmgr to make the extra one(s) fallback 
boot devices.

Use a hook in initramfs-tools to make /boot/efi[2..N] match /boot/efi 
whenever kernels get installed/modified.

Phil