Time Synchronization
To make time on the server relevant, you need to configure NTP. Network Time Protocol (NTP) is a network protocol to synchronize the computer’s internal clock using networks with variable latency.
Install ntp service:
CentOS 6/7
yum -y install ntp
Ubuntu
apt-get install ntp
To synchronize at the moment:
ntpdate pool.ntp.org
Start ntpservice:
CentOS 6
service ntpd start
CentOS 7
systemctl start ntpd
Ubuntu
service ntp start
Add ntp service to startup:
CentOS 6
chkconfig ntpd on
CentOS 7
systemctl enable ntpd
Ubuntu
update-rc.d ntp defaults