Rook and ceph on kubernetes
Use kubectl describe pod <name> -n rook-ceph to see the list of events, it is on the bottom of the output. This will show where the pods get stuck.
It may be also the case that one of your nodes is in bad state, as it seems that some pod replicas are failing to start. You can confirm by running
kubectl get pod -o wide | grep -v RunningPossible all failing pods are running on the same node. If that is the case you can inspect the problematic node with
kubectl describe node [node]