Ubuntu LTS update

Release upgrade

ex. 18.04.x -> 20.04

$ sudo do-release-upgrade -d

Minor upgrade 16.04.x -> 16.04.3


ex. 16.04.2 -> 16.04.3
20.04, Not available now.(June 10)

DeskTop:

$ sudo apt install --install-recommends linux-generic-hwe-16.04 xserver-xorg-hwe-16.04

Server:

$ sudo apt install --install-recommends linux-generic-hwe-16.04