Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I have a virtual machine(VirtualBox) running Ubuntu server. When i issue date -s 2011-01-01 it changes the date, but after a few seconds, the date resets itself to the real time. I do not have any ntp service running (althrough i'm not sure how to check, but i dont see any ntp proceeses starting in this interval)

share|improve this question
Do you have vmware tools installed? – Cakemox Nov 7 '10 at 18:51
i use vbox, not vmware, and yes, i have "guest additions" installed – quamis Nov 7 '10 at 18:54
Also check your crontabs for ntpdate. – Dennis Williamson Nov 7 '10 at 21:34
up vote 4 down vote accepted

If you don't have ntp running than it appears that Guest Additions is resetting the date to that found in the VM virtual bios. Have a look at this discussion for some more information and some scripts to change the vbios date/time.

share|improve this answer

I would suggest checking the time against hwclock to see what the VM hardware clock thinks the time is. Note you should never ever run ntp under a VM, as it is not basing its drift on a real physical clock, so can royally mess up in all sorts of nasty ways. As long as the physical host runs NTP well then the clocks within the VM's are going to be just as accurate.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.