Software RAID

EFI and RAID

While installing Debian 12, it was impossible to setup RAID during the install. Grub would fail installing.

The alternative is to install without RAID, and add RAID afterwards. This shows how to proceed, based on this link: https://unix.stackexchange.com/questions/644108/raid-1-of-boot-efi-partition-on-debian

1. Backup the content of /boot/efi to another location: midir /efi-backup && cp -R /boot/efi /efi-backup

2. umount /boot/efi

3. mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 --metadata=1.0 /dev/sda1 /dev/sdb1

4. mkfs.vfat /dev/md0

5. Find the UUID of the md partiton: ls -alh /dev/disk/by-uuid

6. Change /boot/efi entry in fstab with the new UUID

7. mount /boot/efi

8. Copy the content back to /boot/efi

9. Make sure both devices have the boot flag enabled

10. Test removing a disk and booting. Test the other way around