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If there is a virtual machine running on Hyper-V and it is set to synchronize clock with an Internet time service, will this also correct the hardware clock on the management OS which is hosting this virtual machine?

The virtual machine has Internet connection, but the management OS does not (it's permanently offline).

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Short answer: No, it won't. The virtual machine has no ability to modify the physical hardware clock. –  David Schwartz Jul 24 '12 at 19:25
    
@DavidSchwartz: The hardware clock is only used when booting and shutting down, I think. The OS keeps its own time while running. –  grawity Jul 24 '12 at 19:28
    
@grawity: That is correct. For the virtual machine, the hardware clock is faked when it tries to read it (it just gets the host's time). But writes to the hardware clock from the virtual machine don't do anything. –  David Schwartz Jul 24 '12 at 19:29
    
@grawity: Does synchronization in general affects hardware clock or does it only correct OS time and I have to correct clock manually (like in BIOS or by other methods)? –  User Jul 24 '12 at 19:56
    
@User: Depends on the OS, but usually it adjusts both. For example, in Linux, normally the hardware clock is only written as part of shutdown process – however, if a NTP client is active, then the kernel adjusts the hardware clock every 11 minutes. –  grawity Jul 24 '12 at 22:43

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The host should be set up for synchronization, not the guest. The guest should run a time server (e.g. ntpd) and should be connected to the host over i.e. host-only networking

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