Support booting from LVM/RAID0 (mdadm) on Oracle Cloud with sda as boot volume and sdb+sdc as RAID0

[dopaemon]

Hi, thank you for this great project!

I'm trying to install Debian using debi on Oracle Cloud with the following disk setup:

• /dev/sda (50GB) — Boot volume (EFI, GRUB)
• /dev/sdb (50GB) and /dev/sdc (50GB) — Intended to be configured as a RAID0 (mdadm) or LVM volume for root (/)

My goal is:

• Use /dev/sda to host the EFI and GRUB bootloader
• Combine /dev/sdb and /dev/sdc into a RAID0 array (/dev/md0) or LVM volume
• Install the root filesystem (/) on the RAID0 or LVM
• Successfully boot into the OS from /dev/sda while loading the root from the RAID0/LVM setup

I've encountered issues when trying this manually:

• mdadm isn't available in the initramfs unless explicitly added
• GRUB sometimes fails to detect the RAID/LVM root device during boot
• I'm not sure how to modify debi to prepare the initrd or install mdadm/lvm inside the target correctly

My questions:

1. Is this use-case currently supported by debi?
2. If not, what would be the correct way to extend or patch debi to support RAID0/LVM root setups?
3. Do you have recommendations for integrating mdadm/lvm setup into the debi workflow (e.g., hooks to run pre-/post- chroot, install additional packages, etc.)?

Any guidance would be greatly appreciated. Thanks in advance!