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Additionally, unless you do an mdadm software RAID using full disks, you cannot ensure that the EFI system partition will be RAIDed. But if you want to avoid h

by bradfa 8y ago

Additionally, unless you do an mdadm software RAID using full disks, you cannot ensure that the EFI system partition will be RAIDed. But if you want to avoid having your mdadm metadata at the start of the drives, you can have it placed in various locations which may help, see: https://raid.wiki.kernel.org/index.php/RAID_superblock_formats#Sub-versions_of_the_version-1_superblock https://raid.wiki.kernel.org/index.php/RAID_superblock_forma... I use mdadm RAID1 on full disks on my desktop with the metadata at the end of the disks (superblock version 1.0). Partitioning tools will complain that my backup GPT partition table is invalid and offer to fix it (I always politely decline) but the primary one is fine. My Dell desktop doesn't mind this situation and also does not ever write any data into the EFI partition so it works well for me.

shawnz 8y ago
Why would you want the EFI system partition inside of a RAID volume that's not understood by your system firmware?
- bradfa 8y ago
  When my OS updates the bootloader it stores in the EFI system partition, I want that data to be RAIDed. I set the EFI boot order to use the first disk's EFI system partition then the second disk's. Because at the OS level they are RAIDed and because I put the mdadm metadata at the ends of the disks, the UEFI firmware sees them as normal GPT partitions (with the secondary GPT partition table corrupted at the end of the disk due to mdadm data). When the EFI firmware runs, it should only be performing reads from either of the disks and even if one entire disk is dead it can still boot the system.