Currently, ACS provides the ability to deploy a VM from a template or ISO. However, ACS does not provide the ability to deploy a VM(s) directly from a VM snapshot.
VM snapshots are stored in the primary storage and have a hierarchical or parent/child relationship. The requirement would be to provide the ability to deploy user instances from selected VM snapshots. Additionally, any VM snapshot in the hierarchy can be deployed concurrently.
Even though this can be supported and applicable to all hypervisors, to start with this feature is supported only for VMware hypervisor.
Feature specification is at https://cwiki.apache.org/confluence/display/CLOUDSTACK/Deploy+instance+from+VM+snapshot