My Ubuntu Apache2 Web Server is currently on my VMWare 6 server. I will be migrating it over to the Hyper-V server soon. I could use migration tools to move it. I usually just manually do it.
/boot: 2GB: I could make it 1.5GB. I have had it contain many kernels and crash.
/ or root parititon: 50GB: The Apache2 Web Server using MariaDB as its database. I put it in its own vDisk to protect it as files grow on the web site.
/var: 600GB: The Apache2 Web Server is in /var/www