When deploying a virtual infrastructure it is very important to configure a time server. Lately, most VMware solutions depend on accurate time. For the labs that i deploy, i generally configure the time server on a windows machine(For e.g. AD Machine), and let all the ESXi hosts synchronize time with this windows machine. The windows machine will synchronize time from a internet time server, for e.g. pool.ntp.org(The esxi hosts will not have access to the internet)

In order to configure a windows machine as a time server, run the below command:

C:\\> w32tm /config /manualpeerlist:"0.pool.ntp.org" /syncfromflags:manual /reliable:yes /update

To configure the ESXi host to use the above configure windows machine as its NTP server, use the windows machine’s ip/hostname as the time server and follow the instructions in the following VMware KB, http://kb.vmware.com/kb/2012069

To validate if the ESXi host is synchronizing correctly with the time server, run the command:

watch ntpq -p

The output of the above command will be similar to:

To figure out what the above fields mean, refer the VMware KB article, http://kb.vmware.com/kb/1005092