title: How to split MongoDB replicaset in two replica sets
body: <p>We have a mongoDB replicaset with 6 members (one master and 5 secondaries), split on two continents.</p>
  
  <p>We need to create two replicasets from the big one. All members are in sync.</p>
  
  <p>How can this be done?</p>
  
  <p>Thank you.</p>