Migrating from an existing Ubuntu install

[isZYKerman]

I want to migrate an existing Ubuntu install into a ZFS pool. Here is what I have done:

1. Run rsync -avhH <mounted existing system> <mounted USB driver>
2. Follow the instructions here, but change the debootstrap noble /mnt step into rsync -avhH back, and then skip the Ubuntu configuration step

Now the system does not want to start. It stucks at Booting /boot/vmlinuz-6.11.0-26-generic for System/ROOT/ubuntu. I tried interrupting the boot progress, chroot into my system in ZBM and update-initramfs -c -k all. The output was like several

W: mkconf: MD subsystem is not loaded, thus I cannot scan for arrays.
W: mdadm: failed to auto-generate temporary madam.conf file.

but no errors were thrown out.

What should I do now?

[isZYKerman]

My fault. I skipped the configuration step and thus did not install the zfs-initramfs package.