Re: raid1 root device with efi

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

在 2024/3/9 07:09, Matt Zagrabelny 写道:
> Greetings,
>
> I've read some conflicting info online about the best way to have a
> raid1 btrfs root device.
>
> I've got two disks, with identical partitioning and I tried the
> following scenario (call it scenario 1):
>
> partition 1: EFI
> partition 2: btrfs RAID1 (/)

This really depends on how you want to setup your bootloader.

In my case, I hate GRUB2 so much that I always go with:

- Partition 1: EFI (also as /boot)
   This includes both the EFI bootloader (systemd-boot), along with
   kernel and its initramfs.

   The disadvantage is, if you go LUKS, your kernel/initramfs will never
   be encrypted, thus exporting some risks (e.g. some attacker with
   physical access to your system can implant some rootkit into your
   initramfs and steal your credential)

- Partition 2: Whatever you want
   It can be btrfs RAID*, or even other fs over LUKS over LVM etc.


>
> There are some docs that claim that the above is possible and others
> that say you need the following scenario, call it scenario 2:
>
> partition 1: EFI
> partition 2: MD RAID1 (/boot)
> partition 3: btrfs RAID1 (/)

At least OpenSUSE TumbleWeed doesn't need a dedicated /boot, and it is
using GRUB2.

So I don't think a dedicated /boot is mandatory.

Thanks,
Qu

>
> What do folks think? Is the first scenario setup possible? or is the
> second setup the preferred way to achieve a btrfs RAID1 root
> filesystem?
>
> The reason I ask is that I followed a guide (for scenario 1) and
> rebooted the computer after each step to verify that things worked.
> After I finished the whole guide, I unplugged one of the disks (with
> the system off) and the BIOS could no longer find the disk. I then
> plugged the disk back in and the BIOS could still not find the disk,
> so something is amiss.
>
> Thanks for any commentary and help!
>
> -m
>