Esxi ntp not updating
Exactly this issue is described at the VMware KB1035833 which states that a NTP service running on a Microsoft Windows Server with default configuration may not response with a correct time for VMware services.
ESXi/ESX support synchronization of time with an external NTPv3 or NTPv4 server compliant with RFC 5905 and RFC 1305.
Note The driver installation may add the /usepmtimer switch in the file.
Once this (/usepmtimer switch) was done the clock was dead on time. I originally noticed this because VMware gave me a helpful tip on my laptop, but this page mentions the same thing: Quote from : VMWare tips and tricks Power saving (Speed Step, C-states, P-States,...) Your power saving settings may interfere significantly with vmware's performance. CPU frequency This should not lead to performance degradation, outside of having the obvious lower performance when running the CPU at a lower frequency (either manually of via governors like "ondemand" or "conservative").
It turns out we had the Internet Time setting turned on in the Windows VM's (Control Panel Internet Time tab) so the guest was getting time updates from two places and the internet time was winning.
Obviously you can “ignore” this error when run (so not a huge deal) but the current design seems a bit dumb.
We still had horrendous drift, although it had shrunk from 15 minutes or more down to the 3 or 4 minute range. for additional information." Cause: This problem occurs when the computer has the AMD Cool'n'Quiet technology (AMD dual cores) enabled in the BIOS or some Intel multi core processors.
Finally in the I found this entry (resides in the folder as the file): "Your host system does not guarantee synchronized TSCs across different CPUs, so please set the /usepmtimer option in your Windows file to ensure that timekeeping is reliable. Multi core or multiprocessor systems may encounter Time Stamp Counter (TSC) drift when the time between different cores is not synchronized.
The operating systems which use TSC as a timekeeping resource may experience the issue.
Newer operating systems typically do not use the TSC by default if other timers are available in the system which can be used as a timekeeping source.
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In my case we are running VMWare Server 2.02 on Windows Server 2003 R2 Standard. I had the VMware Tools installed and set to sync the time.