I have set up an instance with all software and packages I need, and I am trying to build a number of clone instances from it. Following the user-guide rules, I shut off the original instance, create the snapshot and a boot 4 instances from that snapshot. I checked that I have enough resources (vCPUs and RAM) to create 4 more VMs.

New instances are spawned and built, marked as active and running. If I try to ssh them I get a Connection refused error. Checking the log, they are stuck at the public/private rsa key pair generation, with the while eth0 network interface is up and configured. After a soft reboot, they halt at the Net device info table, where everything is fine, but the process does not go through and does not reach to the login prompt.

Obviously, a boot from whichever public image (e.g., Ubuntu 14) works like a charm

I'm struggling with it and I can not figure a way out.