how to remove time synchronization

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sankalpag
Posts: 3
Joined: 5. Feb 2009, 07:44

how to remove time synchronization

Post by sankalpag »

guest win xp sp3
host win 7 pro

plz tell how to remove the time syncro between xp and 7. dont just copy paste the help

Thanks
sankalpag
Posts: 3
Joined: 5. Feb 2009, 07:44

Re: how to remove time synchronization

Post by sankalpag »

any help ?
vbox4me2
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Re: how to remove time synchronization

Post by vbox4me2 »

Remove the guest additions, as they do the syncing.
MarkCranness
Volunteer
Posts: 875
Joined: 10. Oct 2009, 06:27
Primary OS: MS Windows 7
VBox Version: PUEL
Guest OSses: Windows Server 2008 R2; Ubuntu 11.04; Windows 2000 Server; Windows XP

Re: how to remove time synchronization

Post by MarkCranness »

Rather than totally disable all Guest Addition features, you can just disable the time sync function.
You can turn the VirtualBox timesync off, but sometimes the VM then doesn't keep very good time and slips (it might only report 40 seconds of elapsed for every 60 seconds of elapsed real time, or it might be OK).

Or you can apply an offset to the time sync, so that the VM runs hours, days, years etc behind the host, but still maintains time sync.

Disable GA time-sync by editing the parameters passed to the VirtualBox Guest Additions Service (on Windows guests):
  • Open Registry Editor (Start menu>Run...>Type 'regedit' into the 'Open:' field>Click the OK button)
    WARNING: Incorrect editing of the registry can damage your system.
  • Navigate to: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VBoxService
  • Double-click on 'ImagePath'
  • Change the 'Value data:' field to:

    Code: Select all

    system32\VBoxService.exe --disable-timesync
  • Click OK
  • Either reboot the VM, or stop and then restart the 'VirtualBox Guest Additions Service'
    To restart the 'VirtualBox Guest Additions Service':
  • Right-click 'My Computer' on the desktop and select 'Manage'
  • Expand 'Services and Applications' and select 'Services'
  • Find service: 'VirtualBox Guest Additions Service' in the list
  • Right-click>Properties
  • Click 'Stop' button
  • Click 'Start' button
After these steps, timesync will be disabled.
To reenable timesync, repeat the steps but remove the --disable-timesync parameter.

Keywords: time clock sync synchronisation synchronization

OR A time offset can be set using:

Code: Select all

VBoxManage modifyvm "My VM" --biossystemtimeoffset <msec>
... this should set the VM clock to be in sync with the host clock, but <msec> (milliseconds) offset. Negative numbers put the VM clock in the past, positive numbers put the VM into the future.
Last edited by MarkCranness on 12. Jan 2010, 07:33, edited 1 time in total.
sankalpag
Posts: 3
Joined: 5. Feb 2009, 07:44

Re: how to remove time synchronization

Post by sankalpag »

that VirtualBox Guest Additions Service was not present there :(
MarkCranness
Volunteer
Posts: 875
Joined: 10. Oct 2009, 06:27
Primary OS: MS Windows 7
VBox Version: PUEL
Guest OSses: Windows Server 2008 R2; Ubuntu 11.04; Windows 2000 Server; Windows XP

Re: how to remove time synchronization

Post by MarkCranness »

Are the Guest Additions (still) installed? (Is there a VirtualBox icon in the system tray at the bottom right inside the guest?)
If not, then time sync will be disabled.

The time is still set once-only anyway each time the VM boots, even when Guest Additions are not enabled:
At VM boot time, VirtualBox will set the virtual CMOS date and time based on the current host time.
Then, IF Guest Additions are installed (and timesync is not disabled), every 10 seconds an attempt is made to synchronize the time.

If you want the VM time to start at a different time, use the VBoxManage modifyvm "My VM" --biossystemtimeoffset <msec> command, which will give the VM a permanent offset, or reset the time in the VM using a startup command of some sort.
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