This tutorial explains how to modify a minimal image so that it can be booted from ESXi 7+ or VMWare Workstation
The minimal cloud image enables the GRUB_FORCE_PARTUUID option
which means system boots from root filesystem only, and the well-known vmw_pvscsi module is compiled as a kernel module.
Therefore, we need to enable initrd.img to load the vmw_pvscsi driver before mounting the root filesystem.