[time] NTP in a virtual machine ?

Adrian von Bidder avbidder
Sat Nov 25 07:47:19 UTC 2006

On Saturday 25 November 2006 08:08, Parag Mehta wrote:
> Is anyone running a NTP server in a virtual machine and has seen any
> delays or latency ?

Summary: don't.

In vmware, everything todo with time is completely screwed.  Some other 
virtualisation solutions might do a bit better, but generally you really 
shouldn't mess with time inside a vm, but just take it as a resource 
provided from the outside.  

ntp assumes a real clock behind the OS-internal time, and corrects for 
(slow!) drifts in the area of a few ppm, whereas the sumulated clock inside 
a vm will probably be synced anyway, and so will be correct over the long 
range, but as the vm executes from the scheduler of the host machine, it 
will see more or less random, but quite big, jitter which it isn't prepared 
to cope with.

-- vbi

Sterility is inherited. If your parents never had kids, odds are you
wont either.
        -- William R. James in news.admin.net-abuse.email
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 254 bytes
Desc: not available
Url : http://fortytwo.ch/mailman/pipermail/timekeepers/attachments/20061125/cf792e6a/attachment.pgp 

More information about the pool mailing list