[clue-tech] Using Xen to run a VM with a different date?

[mike havlicek]

--- On Wed, 3/11/09, Charles W Downing <chuckdowning at earthlink.net> wrote:

> From: Charles W Downing <chuckdowning at earthlink.net>
> Subject: Re: [clue-tech] Using Xen to run a VM with a different date?
> To: "CLUE technical discussion" <clue-tech at cluedenver.org>
> Date: Wednesday, March 11, 2009, 6:41 AM
> Red Mop wrote:
> > On Tuesday 10 March 2009 09:08:05 pm Jed S. Baer
> wrote:
> >   
> >> Hi Folks.
> >>
> >> Turns out I might need to occasionally run some
> software with the system
> >> date tweaked. Unfortunately, doing a web search
> for something like
> >> "running xen different date" turns up a
> whole lot of date-stamped
> >> articles, etc., that don't talk about how the
> system date in a VM
> >> interacts with the host system date.
> >>
> >> So, before I dive into downloading Xen, and
> setting up a domU, I'd like
> >> to know whether there's any hope for telling
> the OS that it's 2003.
> >>
> >> Anyone have any knowledge on this?
> >>
> >> Thanks,
> >> jed
> >> _______________________________________________
> >> clue-tech mailing list
> >> clue-tech at cluedenver.org
> >>
> http://www.cluedenver.org/mailman/listinfo/clue-tech
> >>     
> >
> > VirtualBox or VMWare without the guest editions and no
> ntp, perhaps?
> >   
> Indeed.  With VirtualBox, one can select a "save
> machine state" as an 
> exit option.  When the OS is started next, it has the saved
> date and 
> time as its starting point.  Unfortunately for me, at
> startup my guest 
> OS resets the time and date on my AIO printer, which I have
> to fix by hand.
> 
> I presume one could set the guest OS's time and date to
> any reasonable 
> choice and do one's thing forever.
> > _______________________________________________
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> >
> >   
> 
> -- 
> Chuck Downing
> Highlands Ranch, Colorado USA 
> 
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I admit I don't yet have experience with Xen, but I assume you want to 
keep the hardware clock sane and the system clock sane  on the host environment. For your guest domU I assume you are asking what flexibility
you have in setting its system clock. I suspect you would want to avoid
a scenario where you are regularly polling say the rtc. A round about way
might be to use ntp/ntpd to a totally rigged time server? Or "really" extend the timzone offset...??

-Mike