Ntpd not running

ntpd

Have confirmed correct server is configured in /etc/ntp.conf
It can ping that server.
It definitely has the ntp package

/home/admin# dpkg -s ntp Package: ntp Status: install ok installed
But the daemon is not running

/home/admin# ps wax | grep ntp 21959 pts/0 S+ 0:00 grep ntp
Status check

/home/admin# ntpstat Unable to talk to NTP daemon. Is it running?
I get this when I try to restart it

/home/admin# systemctl start ntpd Failed to start ntpd.service: Unit ntpd.service failed to load: No such file or directory.

What should try next?

Best Answer

To check the status of ntp you should use:

systemctl status ntp

By modifying the /etc/ntp.conf you should restart the service through:

systemctl restart ntp

The ntpstat report Unable to talk to NTP daemon. Is it running? , you can simply start the ntp service through:

systemctl start ntp

To start the service at boot time:

systemctl enable ntp

Related Solutions

NTPD – Does NTPD Set Hardware Clock?

Similar question was asked on Serverfault.com. This was the answer.

From the hwclock man page on RHEL 4.6:

This mode (we'll call it "11 minute mode") is off until something turns it on.  The ntp
daemon  xntpd  is  one thing  that  turns  it on.  You can turn it off by running
anything, including hwclock --hctosys, that sets the System Time the old fashioned way.

To see if it is on or off, use the command adjtimex --print and look at the value of
"status".  If the "64" bit of this number (expressed in binary) equal to 0, 11 minute mode 
is on.  Otherwise, it is off.

So by the virtue of you running hwclock --set you have likely turned it off. By the same token you can check the output of the adjtimex --print to confirm.

VM with ntpd running but not syncing

Problem solved.

Network issue

The VM had network issues preventing ntpd to succeed. It has two eth interfaces, and the one with the gateway goes through a router we don't manage directly. Although my tests wouldn't show it, I guess some UDP frames were blocked. We set up another VM with another network config and ntpq yielded better results.

Ultimately, we changed the ntp config so that the host broadcasts time locally and all VM synchronize on it. Makes more sense and minimizes load on public ntp servers.

`ntpd` sets clock instantly after a few minutes

One thing that probably mislead me during the tests is that ntpd does not synchronize immediately. I thought it would detect a gap right away and then modify the clock speed so that the clock progressively joins the source clock. In fact, we noticed that (unless ntpd is restarted) the clock is unchanged for a few minutes then all of a sudden it is set what seems instantly. In the meantime, the rightmost columns in ntpq output show that synchronization is going on.

This ntpd behavior probably explains why I thought ntpd didn't work even if it did. I just didn't wait long enough and I didn't understand ntpq output.