The nightly unattended-upgrade (which I've configured to Unattended-Upgrade::Remove-Unused-Dependencies "true";) removed the .old kernel on two different 14.04 LTS servers last night, leaving both with no backup kernel at all.
In fact now that I'm paying attention again, I have quite a number of servers without a /vmlinuz.old.
The nightly unattended-upgrade (which I've configured to Unattended- Upgrade: :Remove- Unused- Dependencies "true";) removed the .old kernel on two different 14.04 LTS servers last night, leaving both with no backup kernel at all.
In fact now that I'm paying attention again, I have quite a number of servers without a /vmlinuz.old.