Hi,
To begin with Cloud services (Web and Worker Roles) which is an Azure PAAS (Platform as a service) offerings are essentially Stateless VM's that are spun up at the time of deployment.
Unlike IAAS VMs which are backed up or Geo-replicated by default, PAAS Cloud Service instances are Hosted on the Host Node and are Not Persistent.
The VHD files are not Stored in a Storage account, instead they are dynamically spun up or destroyed as and when the number of instances are changed.
Hope this answer's your question.
Regards,
Nithin Rathnakar
