When working with nested ESXi environments, sometimes a problem that looks like a simple storage issue is actually caused by the storage layer underneath the nested hypervisor. In my lab, I wanted to create a local VMFS datastore on an additional virtual disk attached to a nested ESXi host. The disk was visible to ESXi, and I was able to create a GPT partition, but creating the VMFS datastore failed. In this short note, I will show how I troubleshot the issue and what was required to make VMFS work when the nested ESXi virtual disk was stored on vSAN.…