I don't see how a parity based implementation can work in a meaningful way across multiple datacenters. You certainly couldn't rebuild if you lost an entire datacenter due to disaster.
Sure you can. Given a system that can tolerate loss of N shares, you need to ensure that no datacenter holds more than N shares. In practice, this means you need many smaller datacenters, not two or three; whether that is economically feasible depends on the provider.
Sure you can. Given a system that can tolerate loss of N shares, you need to ensure that no datacenter holds more than N shares. In practice, this means you need many smaller datacenters, not two or three; whether that is economically feasible depends on the provider.