Our datacenter lost power and after power was restored, we cannot successfully start Vertica.
Many systems (even Linux) are under the control of internal policies.
After a reboot, it is not uncommon for the firewall to enable and start on a Linux server.
This will cause the Vertica inter-node communication to fail and Vertica cannot start.
Check the following log:
catalog/drdata/v_drdata_node000*_catalog/startup.log (your node number will vary).
Look for this message:
"node" : "v_drdata_node0002",
"stage" : "Waiting for Cluster Invite",
"text" : "Invited",
"timestamp" : "2017-09-07 12:23:46.191"
Verify that the firewall if not running and that all nodes in the Vertica cluster can talk to each other on the network.