[CentOS] system time automatically fowards in time and then comes back to normal

Sun Nov 22 17:07:14 UTC 2009
Benjamin Franz <jfranz at freerun.com>

nate wrote:
> Akemi Yagi wrote:
>   
>> for VMware products including ESX and ESXi.  According to their
>> current recommendations, " In all cases use NTP instead of VMware
>> Tools periodic time synchronization."
>>     
>
> I've been using vmware for 10 years, and I've never, ever ever
> gotten NTP to hold sync inside of a VM outside of using a VMI
> enabled kernel.
>   

I've got more than 20 VMs spread over 5 machines (VMware Server 2.x), 
both 32 and 64 bit (hosts and VMs) that hold time perfectly using NTP.

1) Make *SURE* that 'cpuspeed' and any BIOS 'power saving' modes are 
disabled on your host and your VMs. Nothing screws timekeeping like 
having the CPU speed vary.

2) Use 'divider=10' on your grub kernel boot lines for your virtual 
machines.

-- 
Benjamin Franz