Comment 17 for bug 44609

Thanks for the bugreport and the debdiff. AFAICS (please note that I'm not a mdadm expert) the patch generates a mdadm config on the target filesystem. This should actually no longer be needed in order to get a booting system.

From the mdadm "hook" script for initramfs (in natty):

CONFIG=/etc/mdadm/mdadm.conf
...
if [ ! -f $CONFIG ]; then
        # there is no configuration file, so let's create one
        if /usr/share/mdadm/mkconf generate $CONFIG; then
                # all is well
                cp -p $CONFIG $DESTMDADMCONF
                info "auto-generated the mdadm.conf configuration file."
        else
                # we failed to auto-generate, so let the emergency procedure take over
                warn "failed to auto-generate the mdadm.conf file."
                warn "please read /usr/share/doc/mdadm/README.upgrading-2.5.3.gz ."
        fi
...

I unsubscribe ubuntu-sponsors for now, could you please re-subscribe and update the debdiff to the latest
version if it turns out that this needs more than what mdadm is doing now.