To synchronize services across multiple machines, you must install NTP. The examples in this guide configure the controller node as the reference server and any additional nodes to set their time from the controller node. Install the ntp package on each system running OpenStack services: # apt-get install ntp # yum install ntp # zypper install ntp Set up the NTP server on your controller node so that it receives data by modifying the ntp.conf file and restarting the service: # service ntpd start # chkconfig ntpd on # service ntp start # chkconfig ntp on It is advised that you configure additional nodes to synchronize their time from the controller node rather than from outside of your LAN. To do so, install the ntp daemon as above, then edit /etc/ntp.conf and change the server directive to use the controller node as internet time source.