Easiest way is to separate them via firewall/network partition so the DC's can't talk to each other, ensure each DC sees the other DC as DOWN, then remove the other DC from replication, then remove all the nodes in the opposite DC using removenode.
- split one DC from a cluster Peng Xiao
- Re: split one DC from a cluster kurt greaves
- 回复: split one DC from a cluster Peng Xiao