How to debug ubuntu boot?

Question

ubuntu

Good afternoon!
After an unsuccessful update, the server ubuntu stopped loading.
Was 13.10, became 14.10, jumping over 14.04 by some miracle
The server does not respond, access is only through hetzner rescue
In the upstart/networking.log it says that
Cannot find device "eth0"
Failed to bring up eth0.
To the upstart/udevtrigger.log
udevadm trigger is not permitted while udev is unconfigured.
udevadm settle is not permitted while udev is unconfigured.
Where to look, what logs or what to do to understand the cause of the error and fix it?
I want the system to start :)

Answer 1

There is a risk that the network card has moved from eth0 to eth1 or eth2.
It was like that when updating Ubuntu with friends.
Try adding settings for them to /etc/network/interfaces by copying from eth0.
If this does not help, then after the line "iface lo inet loopback" add:
and then look from Rescue for the contents of /var/log/iplinks.lst