Configuring controllers to use the same local NTP servers
Using the same NTP servers for all controllers you plan to include in a team helps to ensure that the controller clocks remain synchronized. Keeping the system clocks synchronized is especially important for applications that use the Cassandra database. The controllers in the team must be configured with one or more NTP servers.
Before you create the controller team, configure all the controllers you plan to include in a team to use the same local NTP servers.
You can specify an NTP server for each controller using the controller UI (see .Modifying NTP server or date and time) or using the manual steps below.
Obtain the IP addresses of the local NTP servers for your site. Then ensure that these local NTP servers are the only NTP servers configured for each controller you plan to include in the team.
Log in to the Linux system on which the controller is installed.
Verify that NTP is configured on the system by entering the following command:
~$ ntpdc -c peersIf a list of servers is displayed, one or more NTP servers are configured on the system.
Edit the
/etc/ntp.conffile to remove the entries for servers other than the local NTP server and replace those entries with an entry for the local NTP server:Remove (or enclose in comments by prepending the
#character) all lines that start with the wordserver.Add the following line for each local NTP server, where
local-ntp-ipis the IP address of that local NTP server:serverlocal-ntp-ipiburstSave and close the file.
Restart the NTP service by entering the following command:
~$ sudo service ntp restartVerify that the local NTP servers are the only NTP servers configured on the system by entering the following command:
~$ ntpdc -c peersNTP is configured correctly if the IP addresses for the local NTP servers are the only entries displayed.