> It doesn't specifically. Anaconda will create two EFI boot entries, > each referring to one of the mirror components: > > # efibootmgr -v > BootCurrent: 0001 > Timeout: 1 seconds > BootOrder: 0001,0000 > Boot0000* CentOS Linux > HD(1,GPT,534debcc-f3d6-417a-b5d4-10b4ba5c1f7d,0x800,0x5f000)/File(\EFI\CENTOS\SHIM.EFI) > Boot0001* CentOS Linux > HD(1,GPT,05883d1e-df21-4938-bfa1-ac11ff376572,0x800,0x5f000)/File(\EFI\CENTOS\SHIM.EFI) > # blkid -p -o value -s PART_ENTRY_UUID /dev/sda1 > 534debcc-f3d6-417a-b5d4-10b4ba5c1f7d > # blkid -p -o value -s PART_ENTRY_UUID /dev/sdb1 > 05883d1e-df21-4938-bfa1-ac11ff376572 So far my config looks similar. > >> RAID1 is going to have type FD00 (Linux RAID) whereas EFI firmware >> expects >> type EF00 (EFI System Partition) to boot from. > > > I think you're referring to MBR partition types. I'm not certain, but I > don't see those values in a GPT. No, it's GPT. What does "gdisk -l /dev/sda" show? That would be interesting to see. > > >> EFI then reads the GPT table directly and looks for a vfat filesystem to >> boot from. Default Linux software RAID1 on EL7 uses metadata 1.2 which >> located at the beginning of the partition. EFI won't recognize the vfat >> filesystem behind the RAID metadata. > > > Anaconda knows that it needs to use 1.0 metadata for EFI system > partitions, which is what I mean when I said "the installer should get > the details right." > > # df /boot/efi/ > Filesystem 1K-blocks Used Available Use% Mounted on > /dev/md125 194284 11300 182984 6% /boot/efi > # mdadm --detail /dev/md125 > /dev/md125: > Version : 1.0 OK I see. Do you also have /boot mounted on its own MD device? > >> Maybe certain EFI firmware is more tolerant but at least in my case I >> didn't get it to work on RAID1 at all. >> >> I'd really be interested if someone got it to work, how exactly it's >> configured. How exactly do the GPT tables look, how exactly is the RAID1 >> configured. > > > It might be more useful to know if this is still a problem for you with > the current release. I'm not sure when support for this was added to > Anaconda, but it was fairly recent. You may have last tried this before > that release. IIRC the initial install was with 7.5. Thanks, Simon