I don't follow. Lxc is a Linux thing, so you don't need more than one OS, just one Linux host. And if it really is just nginx + php + mysql, then you don't need

I don't follow. Lxc is a Linux thing, so you don't need more than one OS, just one Linux host. And if it really is just nginx + php + mysql, then you don't need containers at all and can just use a reverse proxy under nginx and have each app talk to a different database within MySQL. Deployment would just be copying over your code. I'm really not sure what you're trying to optimize away here.