Troubleshooting: CRS fails to start

Symptoms

All cluster nodes are up, but CRS is still not able to start.

Solution

Restart OHAS and CRS services using the following command: systemctl restart oracle-ohasd

Cause of the problem

CRS may get stuck in a failed state, unable to open OCR, if during CRS start one or more GRID disk group disks are offline. This is likely to happen in one of the following scenarios:

  • Manual start of CRS after the entire cluster was down and while one of the other nodes is still down
  • While CRS is starting on one of the nodes, another node is rebooted or stopped.

How to prevent the problem

  • Do not start CRS manually while any other node is down. If CRS autostart is enabled then CRS will start automatically after all nodes are up.
  • Always use flashgrid-node reboot command for rebooting a node.
  • Do not reboot more than one node at a time. You can reboot a node only after all other nodes are up, CRS is running, and all disks are online.
  • If you need to reboot the entire cluster, do not reboot the nodes simultaneously. Instead, stop all nodes and then start all nodes.