The above issue was also found in lab installations where disks were not that fast. So on top of what sravuri suggests, you might also want to try to preboot the service-va once you deploy the OVA:
1) Deploy the ova
2) Before starting going into the configurator menu in the console, start up service-va only (power on)
3) Wait for a long time (20m?)
4) Then soft shutdwon the guest os via vsphere
5) Now proceed through the console-based configurator wizard etc