I'm looking for guidance on how to best configure a group of four Windows Server 2008 VMs (two on one host, and two more on another), so that they maintain accurate time, across reboots/shutdowns. I'm using ESX Server 3.5 and vCenter Server 2.5. In particular, I'm trying to do this without a domain controller.
Right now, I have VMware Tools installed on each of the server VMs with 'Time synchronization…' unchecked. Instead, I have Windows setup to automatically update the clock periodically from time.nist.gov. Finally, I have the NTP client is disabled on the two VM hosts (just using the local server time).
With this setup, time remains synced up until the point that I have to restart/shutdown the servers, after which point there is a +/- five to ten second difference between certain servers. I'm sure there must be a better way to do this, however, must articles that I have come across call for a domain controller (which I do not have).
Thanks for any suggestions you may have!
Best Answer
Use VMware Tools to sync time in the guest with the host, and configure your hosts to sync to an NTP server (either on your LAN or out on the Internet).
You can get an obscene level of detail from VMware about timekeeping and best practices in this document.