Lousy timekeeping in VirtualBox 4.0.14

[Li-Lun "Leland" Wang]

On Fri, Dec 16, 2011 at 10:04 AM, Adam Vande More <amvandemore at gmail.com> wrote:
> On Thu, Dec 15, 2011 at 2:11 PM, Larry Rosenman <ler at lerctr.org> wrote:
>> I've set up VirtualBox 4.0.14 on my FreeBSD 10.0-CURRENT (r228498)
>> box, and have a FreeBSD 10.0-CURRENT VM running underneath it.
>> While the VM is running, it doesn't keep time worth a flip.
>
>  There is a bunch of tuning you can do with Virtualbox to try and alleviate
> such issues:
>
> http://www.virtualbox.org/manual/ch09.html#idp13756960
>
> However no combination has worked for me.  The only stable config I've been
> able to find is to setup NTP on host and guest and keep vboxservice
> running.  Running vboxservice alone results in very erratic timekeeping and
> the service core dumps every few days.  Running NTP alone results in the
> difference going too high and out of NTP's allowable range.

I don't remember where I saw it, but have you tried to set the kernel
tunable kern.hz=50 in your guest FreeBSD?  It made a huge difference
to me.

-- llwang