Timekeeping in stable/9
lists at rewt.org.uk
Sat Jan 21 17:24:49 UTC 2012
Ronald Klop wrote:
> On Sat, 21 Jan 2012 14:11:51 +0100, Martin Sugioarto
> <martin at sugioarto.com> wrote:
>> Am Sat, 21 Jan 2012 13:20:51 +0100
>> schrieb "Ronald Klop" <ronald-freebsd8 at klop.yi.org>:
>>> As I understand it.
>>> Host: FreeBSD 9
>>> Guest: WinXP
>>> Which one has troubles with its clock? The host or the guest or both?
>> only inside VirtualBox, I think it's only an application problem and
>> my emails would be probably better addressed to ports at . ONLY the guest
>> is affected when host is loaded.
>> I noticed additionally:
>> You get better results with a desync'ed clock in the guest system, when
>> you start "openssl speed -multi 20" or similar. Within a few seconds the
>> clock gets a 20 seconds difference.
>>> How many CPU's did you assign to the guest?
>>> Did you install virtualbox guest additions to the guest?
>> Here a few details (guest additions are installed):
>> Memory size: 1600MB
>> Page Fusion: off
>> VRAM size: 256MB
>> HPET: on/off (tried both settings)
>> Chipset: piix3
>> Firmware: BIOS
>> Number of CPUs: 1
>> Synthetic Cpu: off
>> CPUID overrides: None
>> ACPI: on
>> IOAPIC: off
>> PAE: on
>> Time offset: 0 ms
>> RTC: local time
>> Hardw. virt.ext: on
>> Hardw. virt.ext exclusive: on
>> Nested Paging: on
>> Large Pages: on
>> VT-x VPID: on
>> 3D Acceleration: off
>> 2D Video Acceleration: on
>>> Do you run NTP on the guest XP also? If yes, turn it off.
>> Windows XP default installation (synch'ed to time.windows.com).
>> Switching this off, does not have any influence. I think MS-Windows
>> does not do continuous synchronization, only at system start, I guess.
>>> VBox guest additions can sync the guest clock with the host.
>> I'll try to deinstall them. But I somehow like my shared folder.
>>> BTW: My experience with VBox is that it is nice for hobby stuff, but
>>> not for heavy load server stuff. VMWare does a better job there.
>> Yes. I know. Still VirtualBox ist nice and cheap solution.
> BTW: I used VBox on Linux at work. Same problems. Different problems
> come and go with different versions of Linux in combination with
> different versions of VirtualBox. Using VmWare ESXI solved it. If you
> search a lot on the vmware website you will find a free version.
In the extreme case I have here, the host isn't taxed at all, cpu, disk
i/o and such are almost idle but the time is skewed dramatically regardless.
For reference the settings I have are:
4 VCPUS (4 physical cores)
ICH9, SAS controller
If I toggle the sysctl in my previous post the problem goes way, and
doesn't return even if the sysctl is changed back... until a reboot of
course. None of the pre-9 guests (there are quite a few spread across a
couple of identical machines) exhibit the behaviour, nor does this
particular one when reverted to a pre-upgrade snapshot, so in this case
it is certainly not the hardware but whatever is used to keep track of
the "ticks" (terminology probably incorrect)
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