Configuring an NTP master server
(Hyper-V only) This procedure configures an NTP master server on the Control Center master host. Perform this procedure only if the host does not have internet access.
- Gain access to the Control Center host, through the console interface of your hypervisor, or through a remote shell utility such as PuTTY.
Start a command-line session as root as follows:
The menu is replaced by a command prompt similar to the following example:
- In the Appliance Administration menu, select Root Shell.
- Select Run, and then press Enter.
Create a backup of the NTP configuration file.
cp -p /etc/ntp.conf /etc/ntp.conf.orig
Edit the NTP configuration file as follows:
- Open /etc/ntp.conf with a text editor.
Replace all lines in the file with the following lines:
# Use the local clock server 127.127.1.0 prefer fudge 127.127.1.0 stratum 10 driftfile /var/lib/ntp/drift broadcastdelay 0.008 # Give localhost full access rights restrict 127.0.0.1 # Grant access to client hosts restrict ADDRESS_RANGE mask NETMASK nomodify notrap
Replace ADDRESS_RANGE with the range of IPv4 network addresses
that are allowed to query this NTP server.
For example, the following IP addresses are assigned to the hosts in a Control Center cluster:
For the preceding addresses, the value for ADDRESS_RANGE is 203.0.113.0.
Replace NETMASK with the IPv4 network mask that corresponds with
the address range.
For example, the network mask for 203.0.113.0 is 255.255.255.0.
- Save the file and exit the editor.
Stop Control Center.
systemctl stop serviced
Enable and start the NTP daemon as follows:
Enable the ntpd daemon.
systemctl enable ntpd
Configure ntpd to start when the system starts.
Currently, an unresolved issue associated with NTP prevents ntpd from restarting correctly after a reboot, and the following commands provide a workaround to ensure that it does.
echo "systemctl start ntpd" >> /etc/rc.d/rc.local chmod +x /etc/rc.d/rc.local
systemctl start ntpd
- Enable the ntpd daemon.
Start Control Center.
systemctl start serviced