Recommended practices for installing large clusters

Apply the following practices when installing large clusters or scaling clusters to larger node counts.

When installing large clusters or scaling the cluster to larger node counts, set the cluster network cidr accordingly in your install-config.yaml file before you install the cluster:

  1. networking:
  2.   clusterNetwork:
  3.   - cidr: 10.128.0.0/14
  4.     hostPrefix: 23
  5.   machineCIDR: 10.0.0.0/16
  6.   networkType: OpenShiftSDN
  7.   serviceNetwork:
  8.   - 172.30.0.0/16

The default cluster network cidr 10.128.0.0/14 cannot be used if the cluster size is more than 500 nodes. It must be set to 10.128.0.0/12 or 10.128.0.0/10 to get to larger node counts beyond 500 nodes.