Time Service


Time services is provided primarily by server-1 using the chronyd daemon. The configuration file for chronyd is /etc/chrony.conf. Service is allowed to all hosts on the admin net (10.1.36). The chronyd uses NRAO primary time servers as its source. The primary RHEL command to query and start/stop chronyd is timedatectl.

RHEL 7 uses chronyd as its standard time server and it is supposed to be somewhat better-behaved than ntpd; ntpd is supposedly preferred in situations with more critical synchronization requirements but that is not the case for the DC correlator. As such, the default time server was used.

Time Sources

The test cluster uses several NRAO time servers; however, these are not available on the USNO cluster. At the USNO two different time servers were provided: tick.usno.navy.mil and tock.usno.navy.mil.


Both clusters use US Eastern time (-0500) with daylight savings (-0400) at the appropriate times of the year. This keeps the two clusters in the timezone of the DC site.

-- JimJacobs - 2020-01-23
Topic revision: r3 - 2020-12-10, JimJacobs
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