Oracle Time Cluster Synchronization Services

https://startupforce.wordpress.com/2013/08/17/disable-ntpd-and-make-ctssd-active-11gr2-rac/ We have two options to synchronize time on our clusters, 1. Using NTP or 2. Using Oracle Cluster Synchronization Services Deamon (ctssd) By default, if a time sync software is running like NTP, ctssd will run in observer mode. In this tutorial we will see how to start ctssd in active mode 1. Check if ctssd is active or not [grid@rac1 ~]$ crsctl check ctss CRS-4700: The Cluster Time Synchronization Service is in Observer mode. [grid@rac2 ~]$ crsctl check ctss CRS-4700: The Cluster Time Synchronization Service is in Observer mode. We can see that CTSSD is in observer mode 2. De-configure NTP. #crsctl stop crs #/sbin/service ntpd stop #chkconfig ntpd off #chkconfig --list ntpd #mv /etc/ntp.conf /etc/ntp.conf.original #rm /var/run/ntpd.pid 3. Start the cluster on all nodes #crsctl start cluster 4. Check that ctssd automatically starts in active mode as CRS-4701: The Cluster Time Synchronization Service is in Active mode. CRS-4702: Offset (in msec): 0 [root@rac2 etc]# crsctl check ctss CRS-4701: The Cluster Time Synchronization Service is in Active mode. CRS-4702: Offset (in msec): 0