One of my linux server's clock loses 10 minutes every now and then, nearly every week. I update the time so it stays correct, and although it doesn't really bother me, i'd like to fix it.
I've been searching around a bit. Nothing can be responsible in the crontab, and i can't find any related message in the logs.
Some people seem to use ntp to fix that kind of issue, but i'd prefer not to use an unecessary component on it.
Uname result :
Linux unis-monitor 2.6.32-5-686 #1 SMP Mon Feb 25 01:04:36 UTC 2013 i686 GNU/Linux
Cat message :
cat messages
Jul 14 06:25:06 unis-monitor rsyslogd: [origin software="rsyslogd" swVersion="4.6.4" x-pid="882" x-info="http://www.rsyslog.com"] rsyslogd was HUPed, type 'lightweight'.
Jul 15 06:25:05 unis-monitor rsyslogd: [origin software="rsyslogd" swVersion="4.6.4" x-pid="882" x-info="http://www.rsyslog.com"] rsyslogd was HUPed, type 'lightweight'.
Cat syslog
cat syslog
Jul 15 06:25:05 unis-monitor rsyslogd: [origin software="rsyslogd" swVersion="4.6.4" x-pid="882" x-info="http://www.rsyslog.com"] rsyslogd was HUPed, type 'lightweight'.
Jul 15 06:39:01 unis-monitor /USR/SBIN/CRON[15272]: (root) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -delete)
Jul 15 07:09:01 unis-monitor /USR/SBIN/CRON[15465]: (root) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -delete)
Jul 15 07:17:01 unis-monitor /USR/SBIN/CRON[15521]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Jul 15 07:39:01 unis-monitor /USR/SBIN/CRON[15662]: (root) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -delete)
Jul 15 08:09:01 unis-monitor /USR/SBIN/CRON[15855]: (root) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -delete)
Jul 15 08:17:01 unis-monitor /USR/SBIN/CRON[15911]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Jul 15 08:39:01 unis-monitor /USR/SBIN/CRON[16052]: (root) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -delete)
Jul 15 09:09:01 unis-monitor /USR/SBIN/CRON[16273]: (root) CMD ( [ -x /usr/lib/php5/maxlifetime ] && [ -d /var/lib/php5 ] && find /var/lib/php5/ -type f -cmin +$(/usr/lib/php5/maxlifetime) -delete)
So if you have any clue of where to look or what i could use to monitor those date change ?
Here is some more infos : the server is a virtual server hosted on HyperV on a win 2012 server. Don't know if it changes anything, seen the other servers hosted don't have this issue…
Best Answer
HyperV is the disease, NTPd is the cure.
Where to look or what i could use to monitor those date change?
You can query the NTPd daemon (via the
ntpqclient) to get the difference between local clock and the NTPd servers reference clock. But that implies actually running NTPd so you are not monitoring your changes alone, you're monitoring the combined effect of your running local clock and NTPd keeping it in sync.I don't actually know if you can configure NTPd to run (and give you the above mentioned metrics) but not to actually adjust the system clock. A different, and less efficient, way would be to periodically (cron?) run
ntpdate -qagainst a set of reference NTPd servers and monitor its output, which will give you the difference between your clock and the reference without actually touching the local clock. Output will be like this:You could filter the last number and graph it to get a nice view of how much and when your clock jumps around: