VDP 5.1 configuration

Currently, we upgraded our Vcenter to 5.5 and it can't support VDR anymore.

We planned to install VDP 5.1 in our new Vcenter.

Here I have few question on the setup of VDP:

1. Can VDP have 4 appliances in one ESX host?

2. Can we configure 2 disk , each with 1.5TB in one appliance?

3. Can we mount back the old VDR disk in VDP appliance and use back the old data?

4. Can we install VDP without uninstall VDR from Vcenter?

Thanks,