I have a machine with fairly old Ubuntu-16.04.7 LTS. I kept packages up-to-date and regularly updated them, however didn't upgrade the whole distro, including kernel and system libraries. Now every time I log in, I get the message that new release 18.04.5 LTS available.
I wonder if I'm safe to upgrade from 16.04.7 to 18.04.5, are there any obstacle on the way? I've never done this before.
One of the potential problems I see, is that I had to update some packages to latest versions, not available in repositories of Ubuntu-16.04.7, also I'm not running a stock kernel (
4.15.0-13-generic which was shipped with the distro), but 4.15.0 (which I built myself, can't remember the reason, I think the stock kernel could not recognize some of my hardware, either
WiFi or video card). Would it be a problem if I upgrade the distro with non-stock kernel?