Ubuntu ntp not updating time
While all computers contain a hardware clock (called the RTC – or real-time clock) most operating systems do not rely on this clock.
Instead they read the time from this clock once (when they boot) and then they use their own internal routines to calculate how much time has passed.
Once inside the guest operating system – these time readings are then delivered to the Windows time keeping infrastructure in the form of an Windows time provider (you can read more about this here:
These time samples are correctly adjusted for any time zone difference between the management operating system and the guest operating system.
The reason for this is that “time zones” are a construct of the software that runs in a virtual machine – and is not communicated to the virtual hardware in any way.
So – in short – when we start a virtual machine there is no way for us to know what time zone the guest operating system believes it is in. As I have mentioned above – all time synchronization that is done by the Hyper-V time synchronization integration service is time zone aware.
The way it does this is by getting time readings from the management operating system and sending them over to the guest operating system.
This is done without the use of the Hyper-V time synchronization integration servers (it happens long before the integration services have loaded).
The downside of this approach is that this does not take into account any potential time zone differences between the management operating system and the guest operating system.
This real-time clock is backed by a small battery (you have probably seen the battery yourself if you have ever pulled apart a computer).
Unfortunately virtual machines do not have any “batteries”.