Stand alone NTP Server (Guest) always 4 hours behind Host Machine.

Discussions related to using VirtualBox on Windows hosts.
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Jetras
Posts: 20
Joined: 14. Sep 2021, 21:06
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows (2012 & 10), Linux (RHEL, Ubuntu, CentOS), FreeBSD (pfSense)

Stand alone NTP Server (Guest) always 4 hours behind Host Machine.

Post by Jetras »

I have a Stand Alone NTP Server (VM CentOS/chrony) that is providing Time for my Virtual Network. It takes time from the Host machine (Windows 10), but upon boot, it is ALWAYS 4 hours behind the Host Time. Both machine TZs are EDT. It's almost as if the NTP Server is taking the HOST RTC as UTC instead of EDT.

Is there anyway to edit Chrony to give it an offset of these 4 hours? I can manually adjust the time each time I boot the VM, but that is getting awfully annoying.
Last edited by Jetras on 1. Oct 2021, 22:06, edited 1 time in total.
Shoot for the Moon, even if you miss you still made it among the stars!
Jetras
Posts: 20
Joined: 14. Sep 2021, 21:06
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows (2012 & 10), Linux (RHEL, Ubuntu, CentOS), FreeBSD (pfSense)

Re: Stand alone NTP Server (Guest) always 4 hours behind Host Machine.

Post by Jetras »

Always find the answers right AFTER I post...

Code: Select all

VBoxManage modifyvm <name> --biossystemtimeoffset <msec>
Used that code to offset the NTP vm and now everything lines up properly...
Shoot for the Moon, even if you miss you still made it among the stars!
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Stand alone NTP Server (Guest) always 4 hours behind Host Machine.

Post by mpack »

Personally I think you had it backwards. Having the host RTC always report UTC is a good thing. It was the VMs that were set up wrong.
Jetras
Posts: 20
Joined: 14. Sep 2021, 21:06
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows (2012 & 10), Linux (RHEL, Ubuntu, CentOS), FreeBSD (pfSense)

Re: Stand alone NTP Server (Guest) always 4 hours behind Host Machine.

Post by Jetras »

mpack wrote:Personally I think you had it backwards. Having the host RTC always report UTC is a good thing. It was the VMs that were set up wrong.
The Host is a laptop that is still used and needs to be at local time as to not cause confusion. The VM is the NTP Server for a Virtual Network of our product line that needs to be sync'd. I don't need an environment where someone can "fix" the time on the Host and it cause issues in the VM Network. This is a Training Lab with multiple people who know enough to be dangerous will have access to the Host Machine.

So I know its not ideal, but it does what I need it to do in a manner that won't cause people to "help".
Shoot for the Moon, even if you miss you still made it among the stars!
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Stand alone NTP Server (Guest) always 4 hours behind Host Machine.

Post by mpack »

Jetras wrote: The Host is a laptop that is still used and needs to be at local time as to not cause confusion.
That doesn't conflict with what I said. The issue is not what the host time is set to, but what time it reports to the VM. Having UTC reported to the VM should be be fine, then all you need do is apply the appropriate time zone offset in each guest. Having the host lie about the time in order to avoid normal configuring of the guests... seems unusual to me.
Jetras
Posts: 20
Joined: 14. Sep 2021, 21:06
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows (2012 & 10), Linux (RHEL, Ubuntu, CentOS), FreeBSD (pfSense)

Re: Stand alone NTP Server (Guest) always 4 hours behind Host Machine.

Post by Jetras »

The NTP VM was seeing the HOST's EST Time as UTC. I couldn't figure out why it was doing that. The offset to the NTP VM corrected that. Where do I change how the Host reports time to the VM?
Shoot for the Moon, even if you miss you still made it among the stars!
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