Clusterware(CRS) not coming up:-
1. From root user check crs :-
# crsctl check crs
CRS-4638: Oracle High Availability Services is online
CRS-4535: Cannot communicate with Cluster Ready Services
CRS-4529: Cluster Synchronization Services is online
CRS-4533: Event Manager is online
2. Try to stop and start it:-
# crsctl stop crs
CRS-2796: The command may not proceed when Cluster Ready Services is not running
CRS-4687: Shutdown command has completed with errors.
CRS-4000: Command Stop failed, or completed with errors.
# crsctl check crs
CRS-4638: Oracle High Availability Services is online
CRS-4535: Cannot communicate with Cluster Ready Services
CRS-4529: Cluster Synchronization Services is online
CRS-4533: Event Manager is online
# crsctl start crs
CRS-4640: Oracle High Availability Services is already active
CRS-4000: Command Start failed, or completed with errors.
3. Stop High availabilty service and crs resources:-
crsctl stop res -init -all
crsctl stop has
Verify no crs processes should be running :-
ps -ef|grep d.bin
Note: Kill if any process is still running .
4. Now start crs :-
crsctl start crs
ASM instances and databases will also come up in current node.
5. If any ASM Disk group is dismounted then :-
ALTER DISKGROUP <Disk_Group_Name> MOUNT;
