Run Ubuntu Installer from any GRUB-based system

So if I have a KVM VPS and the VPS provider doesn't provide Ubuntu 16.04 images nor mounting ISO images…

  1. Get ISO from http://cdimage.ubuntu.com/netboot/.
    wget -O/tmp/mini.iso http://mirrors.zju.edu.cn/ubuntu/dists/xenial/main/installer-amd64/current/images/netboot/mini.iso
  2. Unpack the ISO to /livecd.
    apt install p7zip-full
    mkdir /livecd
    cd /livecd
    7z x /tmp/mini.iso
  3. Reboot and spam / or hold Ctrl to enter GRUB menu
  4. Press C to enter GRUB console
  5. Enter one of the following code snippets into the console
xenial-netboot-install.cfg
linux	/livecd/linux --- quiet
initrd	/livecd/initrd.gz
boot
xenial-netboot-expert-install.cfg
linux	/livecd/linux priority=low ---
initrd	/livecd/initrd.gz
boot
xenial-netboot-rescue.cfg
linux	/livecd/linux rescue/enable=true --- quiet
initrd	/livecd/initrd.gz
boot

Use netboot ISOs only! Otherwise, the installer will complain not mounting the CD.