In ESX, the model of how ESX accesses NFS storage of ISO images that are used as virtual CD-ROMs for virtual machines is different from the model used in ESX Server 2.x.

ESX has support for VMkernel-based NFS mounts. The new model is to mount your NFS volume with the ISO images through the VMkernel NFS functionality. All NFS volumes mounted in this way appear as datastores in the vSphere Client. The virtual machine configuration editor allows you to browse the service console file system for ISO images to be used as virtual CD-ROM devices.