Hi Daniel -
You’d make a new Vault instance, clusterB, init and unseal and login to that… Then, restore the snapshot from clusterA using the -force flag, then unseal and login with the clusterA unseal key(s) and token.
I put a pseudo-sample-sh of this here: https://gist.github.com/mikegreen/7561191dffc449cce225faeca8a35cc8
It isn’t meant to run entirely, but follow along to prove you can snapshot and use that backup 
3 Likes