Easy steps to install and configure NTP on CentOS
1.
Login as the root user
Type the following command to install ntp
# yum install ntp
2.
Turn on service
# chkconfig ntpd on
3.
Synchronize the system clock with 0.pool.ntp.org server:
# ntpdate pool.ntp.org
4.
Start the NTP:
# /etc/init.d/ntpd start
Configure crontab to use NTP on Linux Machine
1. Stop the ntpd processes
# chkconfig ntpd off
# /etc/init.d/ntpd stop
2. Create a shell script like this
>vi synctime
#!/bin/bash
/usr/sbin/ntpdate ntp.xs4all.nl
3. Add an entry in cron job
>crontab e
#min hour day_of_month month day_of_week user command
*/10 * * * * /home/work/scripts/crons/synctime > /dev/null 2>&1