How do I upgrade kernel to 4.4.0-xx ?
I have built a droplet with Ubuntu-14.04 and immediately upgrade it to a pre-release version of Ubuntu-16.04. Everything seemed working fine, and I installed and set up several servers (apache2, postfix, dovecot, ....) but the kernel remained at 3.17.0-71.
Since the official 16.04 was released, I did "apt-get dist-upgrade," which has installed the kept-back kernels along with many other packages. However, it has made no changes in terms of the kernel version to be booted.
Shortly, I found that on a digitalocean droplet, the kernel should be selected in the control panel. I did select Ubuntu-16.04 kernel-4.4.0-21 in the menu and started the droplet but it wouldn't respond. "Console Access" revealed that the droplet started up but had no ethN I/F.
With putting back the kernel to Ubuntu-14.04 kernel-3.17.0-71, everything has started working properly.
Are there any ways to work around this problem around the missing ethN I/F? Or must I port everything to a newly created droplet?