On 17 Nov 2008 23:08:21 GMT, Steve Kostecke <[EMAIL PROTECTED]> wrote:
>On 2008-11-17, David Woolley <[EMAIL PROTECTED]> wrote: > >> Unruh wrote: >> >>> A question has come up on another newgroup whethr or not the time can >>> be disciplined via ntp (or chrony) on a virtual server. >> >> You should discipline the host and run vmware tools or equivalent on >> the guests. >> >> A link to the VMWare paper on this was posted last week. > >As a courtesy to our many readers, here's the link: > >http://support.ntp.org/bin/view/Support/VMWareNTP We're running about 80-100 VMware linux and Windows servers here under both 2.5.5 and 3.0.3 (though 3.0.3 is far better as is 3.5 which we will be going to around 1/09) and we've had great success with a cron script and vmwaretools (given vmwaretools won't step BACK if you're running fast from what their support tells us). The script is in /etc/cron.hourly and its a one liner called timefix for us and its basically this ntpd -q make sure you have ntpd TURNED OFF on the server and we see precisions easily within 0.10 second. Good enough to get LDAP working etc. in this environment. I wouldn't use a VM as a NTP server but there's no reason not to use ntp on it to keep it in sync with vmware tools and ntp. Also, make sure that you have the TimeSync=True set in the vmware config there's a command line that will do this for you as well that you can run from the vm guest along with the step to add clock=pit to your linux kernel boot lines. 2) Turn off ntpd on new vitual machine chkconfig --level 2345 ntpd off /etc/init.d/ntpd stop 4) check kernel lines for clock=pit vi /boot/grub/grub.conf add them if not there 5) Check VMware setting for tools.timesync=true in vmx file run the following on linux system to set it vmware-guestd --cmd 'vmx.set_option synctime 0 1' Hope this helps someone some, it works for us, but your results may vary. Feel free to write me back off list with any questions. George _______________________________________________ questions mailing list [email protected] https://lists.ntp.org/mailman/listinfo/questions
