Architecting a vCloud Availability for vCloud Director Solution : vCloud Director Configuration : 5.6 vApps and Virtual Machines
   
5.6 vApps and Virtual Machines
A vApp is created in the target Org VDC for each replicated virtual machine. Inside the vApp is a placeholder virtual machine with the same compute (vCPU, RAM) size and operating system as the protected VM. The placeholder VM has certain operations disabled and cannot be moved or powered on by vCloud Director—these operations can be done only through vCloud Availability for vCloud Director APIs.
A vApp is created with the recovery network, and in the case of test failover, an additional test network is added so the recovered VM can be connected to it.
The vApp can be renamed and additional VMs and vApp networks can be added. However, there can be only one recovery VM in a vApp.
The recovery VM has guest customization disabled and its network IP Allocation Mode is set to DHCP which guarantees it will have the same IP and MAC address as the protected VM.
It is possible to change IP address of the recovered VM with guest customization but this must be orchestrated during the failover (see Section 7.4, Failover Orchestration).