A few days ago i ran into an interesting problem where the NDB UI as well as NDB CLI listed one Oracle database and the Database Server virtual machine (VM) as down with the status ERA_DAEMON_UNREACHABLE.
The Database Server VM was up and running and i could access it via ssh via my MacBook, from the NDB Server and the NDB Agent. The database was running and the NDB process perform_work was running on the DB Server VM. After comparing file content on the DB Server VM with another Oracle DB managed by NDB i found that the era_base.loc file was missing in the /home/oracle directory.
I recreated the file with, with one line of content “/opt/era_base” and now everything is back to Normal
