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Server 2012 R2, Hyper-V

In researching my PDC time synchronization problems (noted in this serverfault post) I came across this Microsoft guidance at this link:

"For virtual machines that are configured as domain controllers, it is recommended that you disable time synchronization between the host system and guest operating system acting as a domain controller. This enables your guest domain controller to synchronize time from the domain hierarchy. To disable the Hyper-V time synchronization provider, shut down the VM and clear the Time synchronization check box under Integration Services."

This article is dated 2013 and includes this note as well:

"This guidance has been recently updated to reflect the current recommendation to synchronize time for the guest domain controller from only the domain hierarchy, rather than the previous recommendation to partially disable time synchronization between the host system and guest domain controller."

While this seems straightforward enough, it was the first time I was exposed to Hyper-V Integration Services. They seem useful enough.

Is there some reason to NOT install Integration Services as a 'rule of thumb'?

Addendum to post: When I clicked on 'Insert Integration Services Setup Disk' from the VM's 'Action' menu, the virtual DVD loaded. I didn't specifically say run. When I was later ready to install Integration Services I right clicked the DVD and selected 'Install Hyper-V Integration Services', but a window popped up saying integration services were already running.

Are integration services installed by default now, or is it a VM setup choice that isn't that evident? I checked all my VM's in Hyper-V and now see it's installed on every one of them. I suppose that would make this a 'moot' question, except that there may be others like me who are unaware of this feature being automatically installed. If it's automatically installed, why would there be a selection under the VM Actions menu to install it?

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Alan
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2 Answers2

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Generally: NO. Some services at times may be inconvenient (time for a DC was the only case I knew) but the drivers alone are good for performance. Have you ever looked at the hardware simulated for a network card? It is SLOW. The enlightened drivers are the way to go.

And they are in any decent OS anyway. This includes recent versions of Linux (Hyper-V drivers in the kernel). You have to get ancient or fringe to not have the stuff already prepared.

TomTom
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  • I certainly see why I would stay away from simulated interfaces! Thanks also for confirming the need for integration services WRT DC's. Do note my addendum to post (our posts crossed in timing). In view of your recommendation and rationale, I'm surprised to find integration services automatically installed. Finally, I keep seeing the term 'enlightened' show up in and around these discussions. Would you mind explaining why that term is used? – Alan Jul 08 '15 at 14:52
  • Enlighted drivers are special drivers that bypass the virtualization. The Hyper-V SCSI driver is not going against simulated hardware, it talks to the hypervisor through a special software bus - it is "enlighted" to the fact is runs in a Hypervisor. – TomTom Jul 08 '15 at 14:59
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Integration Services comes pre-installed in a number of supported guest Operating Systems. In others you need to upgrade or install Integration Services after the guest OS installation.

To the question Should integration services always be installed on a Hyper-V VM? the answer is most probably yes.

The question I think you're really asking is whether or not you should enable or disable specific Integration Services. As you've seen from your previous question, that depends. Have a read at the link below for more detailed information about Integration Services. Make sure to follow the links regarding the supported guest Operating Systems.

https://technet.microsoft.com/en-us/library/dn798297.aspx

joeqwerty
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