I use VMware VirtualCenter 2.5.0 Build 147697 and VMware ESX 3.5.0 143128 and it was not possible to configure the timeserver of the ESX hosts through the VirtualCenter (VC). Normally you should ajdust the timeserver settings for the ESX hosts in VC by clicking on the ESX Server –> Configuration –> Software: timeserver configuration –> Preferences. But this does not work for me, so i had to adjust the timesever directly on the ESX hosts.
First login to your ESX with ssh and become super-user.
$ ssh -l user esx-server1.your.domain $ su - $ ln -sf /usr/share/zoneinfo/Europe/Berlin /etc/localtime $ cp /etc/ntp.conf /etc/ntp.bak $ vi /etc/ntp.conf restrict default ignore restrict 127.0.0.1 restrict 132.230.1.9 mask 255.255.255.255 nomodify notrap noquery server 132.230.1.9 driftfile /var/lib/ntp/drift
You have to set the timeserver to your needs (my timeserver has the IP 132.230.1.9) before saving the file. Then put the same IP in the file /etc/ntp/step-tickers.
$ cp /etc/ntp/step-tickers /etc/ntp/step-tickers.bak $ echo "132.230.1.9" >/etc/ntp/step-tickers
To see the offset in seconds you can run the command ntpdate -q 132.230.1.9 as super-user. Now it’s time to restart the ntpd daemon and enable it for autostart. The last command set the hardware clock to the synchronized local time.
$ esxcfg-firewall -e ntpClient $ service ntpd restart $ chkconfig --level 345 ntpd on $ hwclock --systohc
Finally reboot the ESX server through the VC (don’t forget to migrate running virtual machines to another ESX node) so that the timeserver configuration will be visible in VC.
