The key data functions are Access, process & Store

Abstraction. often via virtualization. frees the resources from their physical constraints to enable pooling. Then a set of core connectivity and delivery tools(orchestration)ties these abstracted resources together. creates the pools. and provides the automation to deliver them to customers.
Ref: CSA Security Guidelines V4.0

Type II hypervisors are 0S-based and more attractive to attackers. There are lot of vulnerabilities which are found not only on 0S but also in applications residing on the 0S.

IaaS uses the following storage types:
Volume storage: A virtual hard drive that can be attached to a virtual machine instance and be used to host data within a file System, Volumes attached to IaaS instances behave just like a physical drive or an array does. Examples include VMware Virtua Machine File System(VMFS), Amazon Elastic Block Store(EBS), RackSpace Redundant Array of Independent Disks (RAID), and OpenStack Cinder.
Object storage: Similar to a file share accessed via APIs or a web interface. Examples include Amazon S3 and Rackspace cloud files.

Measured service is defined as "Resource usage can be monitored, controlled, and reported, providing transparency for both the provider and consumer of the utilized service. "