RedHat release 7.3 This is a development machine, so I do not know its installation history. It was noticed that it did not keep its time synced very well, although ntpd is running.
My investigations revealed that ntp is working fine but there is another service running that is also updating the time – unfortunately that service is 12 minutes fast!
For example, I disable ntpd and run ntpdate. The computers time is reset.
#timedatectl status
Local time: Tue 2016-11-22 13:27:56 GMT
Universal time: Tue 2016-11-22 13:27:56 UTC
RTC time: Tue 2016-11-22 13:27:17
Time zone: Europe/London (GMT, +0000)
NTP enabled: no
NTP synchronized: no
RTC in local TZ: no
DST active: no
but within a couple of minutes the time goes back to being 12 minutes fast (compare with RTC)
#timedatectl status
Local time: Tue 2016-11-22 13:41:09 GMT
Universal time: Tue 2016-11-22 13:41:09 UTC
RTC time: Tue 2016-11-22 13:28:49
Time zone: Europe/London (GMT, +0000)
NTP enabled: no
NTP synchronized: no
RTC in local TZ: no
DST active: no
I found some relevant messages in /var/log/messages
*Nov 22 14:26:00 development systemd: Time has been changed
Nov 22 14:38:27 development systemd: Time has been changed
*Nov 22 14:27:00 development systemd: Time has been changed
Nov 22 14:39:27 development systemd: Time has been changed
*Nov 22 14:27:00 development systemd: Time has been changed
Nov 22 14:40:27 development systemd: Time has been changed
*Nov 22 14:39:00 development systemd: Time has been changed
Nov 22 14:42:27 development systemd: Time has been changed
The ones marked "*" are where I have done a date 11221426
.
You can see something somewhere resets the time back to being 12 minutes fast. Note the time is always "27 seconds" so it seems to run once a minute, although this slowly drifts (currently running at 28 seconds!).
I spent a long time disabling services but I have not been able to find the one that is forcing my machine to be 12 minutes in the future. ntpd is disabled, but I know that one syncs to the correct time.
Please can anyone suggest any other time updating services that I could check to see if they are running.
Additional information
As suggested in the answers, I looked at chronyd. It was not running on my machine, and even if I have it running it sets the machine to the right time, not 12 minutes fast.
chronyd.service - NTP client/server
Loaded: loaded
(/usr/lib/systemd/system/chronyd.service; disabled; vendor preset: enabled)
Active: inactive (dead)
Best Answer
Red Hat version-7 introduced the
chronyd
daemon for system clock management. It can be used in lieu of thentpd
daemon.chronyd
is favored for systems that may intermittently disconnect from a network.chronyd
can adjust the system time much faster thanntpd
.To see if this daemon is running, do:
To determine how the daemon is operating:
Configuration is controlled via
/etc/chrony.conf
.