VDP is a dead product (although VMware still provides support). Your customer needs to move on to another product that has a future. If this is a vCenter down issue, customer needs to open a support request with GSS immediately.
whats the vcenter version?
Is it windows or appliance?
Are you ready to troubleshoot vcenter issue?
I don't think DB restores are supported in Emergency restores
I think it's only VM restores. Again, its been a while and I might be wrong.