VMWare and slow clocks

I have noticed recently that most of our VMWare instances (and we are running decent fleet of them for the ATG Lab as well as internal system) if left without time synchronization, will loose get late quite a bit: some of them as much as hour or more a week.

Unix date command unfortunately belongs to those commands that I am having troubles to remember and everytime I have to use it with parameters, I end up googling for examples …

The following snippet is useful when correcting only time portion:

[tkuser@jci-app ~]$ date
Sat Jan 3 11:28:12 EST 2009

[tkuser@jci-app ~]$ sudo date -s "13:45"
Sat Jan 3 13:45:00 EST 2009

[tkuser@jci-app ~]$ date
Sat Jan 3 13:45:04 EST 2009
Explore posts in the same categories: Unix

3 Comments on “VMWare and slow clocks”

  1. 1div0 Says:

    Is this 2K9 Zune/TOSHIBA like bug? Almost forty years of development of disinformation technologies and still not able to measure time correctly? And stupidity like DST… only Island is ignoring such non$€n$€. Anyway, wait till 32-bit counter overflows in 38.

  2. Peter M. Says:

    We’ve solved the slow clock problem with NTP time synchronization. The trick is to shorten the poll interval on Windows (default is 1 week). Details can be found at

  3. 1div0 Says:

    I’ve experienced situation where NTP failed. Hardware with clock from 1 company so bad that ntpd was not able to synchronize properly at all. Fixed with periodic call of ntpdate.

    Recent distributions have /etc/init.d/ntpdate service to do just this.

    Win32 junk sometimes synchronized to NTP on Cisco router, but mostly did not. Linux based machines synchronized properly in the same setup.

    So there was only working solution Dimension 4

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