[systemd-devel] "bootctl install" on mdadm raid 1 fails

[Lennart Poettering]

On Fr, 08.12.17 23:33, Bjørn Forsman (bjorn.forsman at gmail.com) wrote:

> Hi all,
> 
> I assumed bootctl would be able to install onto a mdadm raid 1 array
> (mirror). But this happens:
> 
>   $ bootctl --path=/mnt/boot install
>   Failed to probe partition scheme "/mnt/boot": Input/output error
> 
> The raid array is created with --metadata=0.90 (superblock at the end
> of device). systemd v234 was used for testing.
> 
> I see people online that have worked around this by setting up the ESP
> (/boot) manually, and finalizing the install with 2x calls to
> efibootmgr. But I'm hoping for bootctl to handle this for me :-)
> 
> Any ideas?

Hmm, we simply use libblkid on the block device, and validate that
everything is in order, i.e. has a GPT disk label, and all the right
UUIDs and so on. It's very simple code. If that doesn't work, then
either your setup is borked or most likely the bug is in libblkid.

We ultimately don't care much what the backing block device really is,
as long as it exposes a GPT partition table and the kernel exposes
proper per-partition block devices. 

You can check if blkid works properly by running:

# blkid -p /dev/sda1
/dev/sda1: LABEL="SYSTEM" UUID="1234-5678" VERSION="FAT32" TYPE="vfat"
USAGE="filesystem" PART_ENTRY_SCHEME="gpt" PART_ENTRY_NAME="EFI System
Partition" PART_ENTRY_UUID="12345678-1234-1234-1234-123456789abc"
PART_ENTRY_TYPE="c12a7328-f81f-11d2-ba4b-00a0c93ec93b"
PART_ENTRY_FLAGS="0x1" PART_ENTRY_NUMBER="1" PART_ENTRY_OFFSET="2048"
PART_ENTRY_SIZE="532480" PART_ENTRY_DISK="8:0"

we need at least the fields PART_ENTRY_TYPE=, PART_ENTRY_SIZE=,
PART_ENTRY_OFFSET=, PART_ENTRY_NUMBER=, PART_ENTRY_UUID=,
PART_ENTRY_SCHEME= and TYPE= of these. If they are missing, then
either your setup is bad, or blkid confused.

That all said, unless mdadm operates with exactly zero header and
footer on disk I doubt this will ever work and be compatible with
EFI. But then again, I have no clue about mdadm...

Good luck,

Lennart

-- 
Lennart Poettering, Red Hat