Adding new storage to virtual machine - auto select host and storage

Please, describe the problem here and provide additional information below (if applicable) …
in vmware and opennabula, if i want to add another vdisk to a vm, i need to create a new blank os disk, and i also need to select which storage it will seat in. but what happens when i have local storage across hosts? and i want to deploy that new vdisk in the same host that the vm resides? much like when i deploy a new vm and the opennebula elects a host to deploy based on free resources.

is that possible? or i have to manually create a black os disk image for each datastore for each host?

Versions of the related components and OS (frontend, hypervisors, VMs):

Steps to reproduce:

Current results:

Expected results: