NTP Failed with Oracle 11gR2 RAC on Linux

NTP configuration issues with Oracle 11gR2 RAC setup During the Grid infrastructure setup for Oracle 11gR2 RAC, I ran into a weird error with ntp not working with the Grid infrastructure installer. edit ntp configuration on both cluster nodes and restart ntp services. To do so, logon to each node as root and edit  the /etc/sysconfig/ntpd configuration file to make change for options settings as shown below: [root@vxnode2 ntp]# service ntpd stop [root@vxnode2 ntp]# cat /etc/sysconfig/ntpd # Drop root to id 'ntp:ntp' by default. OPTIONS="-u ntp:ntp -p /var/run/ntpd.pid" # Set to 'yes' to sync hw clock after successful ntpdate SYNC_HWCLOCK=no # Additional options for ntpdate NTPDATE_OPTIONS="" now add -x before -u  see below [root@vxnode2 ntp]# vi /etc/sysconfig/ntpd OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid" [root@vxnode2 ntp]# cat /etc/sysconfig/ntpd # Drop root to id 'ntp:ntp' by default. OPTIONS="-x -u ntp:ntp -p /var/run/ntpd.pid" # Set to 'yes' to sync hw clock after successful ntpdate SYNC_HWCLOCK=no # Additional options for ntpdate NTPDATE_OPTIONS="" You will need to restart ntp services for this to take affect: root@vxnode2 ntp]# service ntpd stop Shutting down ntpd: [ OK ] [root@vxnode2 ntp]# service ntpd start ntpd: Synchronizing with time server: [ OK ] Starting ntpd: [ OK ] [root@vxnode2 ntp]# ps -ef|grep ntp root 7363 1 0 03:51 ? 00:00:00 ntpd -x -u ntp:ntp -p /var/run/ntpd.pid Now we can move forward in the 11gR2 RAC Grid Infrastructure setup.