add pstime (psi time servers) to /etc/chrony.conf

to_system/etc/chrony.conf

@@ -0,0 +1,41 @@
+# Use public servers from the pool.ntp.org project.
+# Please consider joining the pool (http://www.pool.ntp.org/join.html).
+server pstime1.psi.ch iburst
+server pstime2.psi.ch iburst
+server pstime3.psi.ch iburst
+server 0.centos.pool.ntp.org iburst
+server 1.centos.pool.ntp.org iburst
+server 2.centos.pool.ntp.org iburst
+server 3.centos.pool.ntp.org iburst
+
+# Record the rate at which the system clock gains/losses time.
+driftfile /var/lib/chrony/drift
+
+# Allow the system clock to be stepped in the first three updates
+# if its offset is larger than 1 second.
+makestep 1.0 3
+
+# Enable kernel synchronization of the real-time clock (RTC).
+rtcsync
+
+# Enable hardware timestamping on all interfaces that support it.
+#hwtimestamp *
+
+# Increase the minimum number of selectable sources required to adjust
+# the system clock.
+#minsources 2
+
+# Allow NTP client access from local network.
+#allow 192.168.0.0/16
+
+# Serve time even if not synchronized to a time source.
+#local stratum 10
+
+# Specify file containing keys for NTP authentication.
+#keyfile /etc/chrony.keys
+
+# Specify directory for log files.
+logdir /var/log/chrony
+
+# Select which information is logged.
+#log measurements statistics tracking