SBS 2011 & Dynamic Memory

by Marin Franković on 17 March, 2011

Month ago I installed SBS 2011 in a virtualized environment, in Hyper-V role of Windows 2008 R2 server to be exact. As all of you already know,  week ago SP1 RTM for R2 server was released and I have installed it on my Hyper-V host. At the same time, I upgraded all my guest OS operating systems to SP1 as well. later on, all guest operating systems where upgraded with new Hyper-V integration components which was a needed step to start utilizing Dynamic Memory. All guest machines happily took on new settings and started using this new feature of Hyper-V. All but SBS 2011 Standard server.

SBS 2011 Standard is supported in virtualized environment, as it is clearly stated in deployment guide:


Installing SBS 2011 as a guest inside a HyperV server parent is fully supported. Installing the HyperV role ON SBS 2011 is not. With the premium add on you can take the Windows Server 2008 R2 standard media and install it as a base for the HyperV role. Then you are licensed to install the SBS 2011 media AND the Windows Server 2008 R2 media as guests inside the Windows 2008 R2 server that you installed the HyperV role. This is referred to as 1+1 licensing and is a supported deployment of SBS 2011. Installing SBS 2011 as a guest inside _any of the virtualisation platforms certified for Windows Server 2008 is fully supported. SBS11 on Hyper-V has an advantage in that there is no delineation of ‘our problem’ vs ‘their problem’ in regard to host/guest operation.

But, for some reason, SBS 2011 is totally ignorant to the Dynamic Memory settings of Hyper-V role. Personally, I do not see a valid reason for it, since SSB 2011 is based on Windows Server 2008 R2 Standard edition which can be and is upgraded to SP1. Of course, when you read Hyper-V Dynamic Memory Guide, there is no mention of SBS 2011 as supported operating system.

Dynamic Memory Supported Operating Systems

I hope that it will be rectified in one f the future patch releases. Until then, I am stuck with fixed size RAM in my SBS 2011 virtual machine.

{ 8 comments… read them below or add one }

Ronny March 17, 2011 at 21:37

A good explanation for not supporting Dynamic Memory it is not supported by Exchange 2010.
read the exchange server requirements under hardware virtualization you find at the bottom, Exchange Server Memory Requirements and Recommendations:


Marin Franković March 18, 2011 at 9:54

Hi Ronny,

thanks for the great piece of information!


David Jones August 18, 2011 at 16:51

Big problems if you install SBS 2011 as a guest into a Hyper-V host that is part of the same SBS domain. I have done this and migrated off SBS 2003. Just finished decommissioning the 2003 server and removed AD. Now my SBS 2011 server can’t start because there are dependencies in the start up of the Hyper-V guests that require domain authentication! Exactly how supported do Microsoft say this configuration is?

The error I’m getting is:
[Window Title]
Hyper-V Manager

[Main Instruction]
An error occurred while attempting to start the selected virtual machine(s).

‘SBSSERVER’ failed to start.

Microsoft Emulated IDE Controller (Instance ID {83F8638B-8DCA-4152-9EDA-2CA8B33039B4}): Failed to Power on with Error ‘There are currently no logon servers available to service the logon request.’


Marin Franković August 18, 2011 at 17:56

Hi David,

it is highly unrecommended to have Hyper-V host OS be a member of a domain that is running in Hyper-V guest OS. Host Hyper-V server should be standalone server in this case.

Best regards


David Jones August 19, 2011 at 0:44

Hi Marin,

Found the following MS blog which had a fix:

Fixing up the permissions on the .vhd worked.

Why would Microsoft make it “highly unrecommendable” to have a Windows Hyped-V server not part of an Active Directory Domain!? I’m not questioning your mention of this fact. I’m just baffled by the limitation and there is no mention of this rather major caveat in the deployment guide! It just says it is fully supported. Makes it sound so simple, doesn’t it! Sheesh… If you have any links or further info from MS on this limitation I would appreciate it.




Marin Franković August 19, 2011 at 2:07

As I sed, it is recomended that host os is not a member of a domain which is hosted in a guest os that is virtualized on it. Since the host os is the first one to boot, dependencis on domain logins may produce errors during services startup.


David Jones August 19, 2011 at 3:50

Hi Marin,

Thanks for the update. Would it be an option to install AD onto the Hyper-V host? The licensing with MS says the host can only be used in the management of the guests and the ability for services to start up on the host to allow the guests to run would qualify, presumably?


PS: My apologies if I have kind of hyjacked your post on dynamic memory! 🙂


Marin Franković August 19, 2011 at 6:47

Hi David,

everything relevant to SBS and virtualization can be found on the following links:

– SBS Licensing FAQ – (applies to 2011 also)

Or if you have any specific question, you can send me an e-mail.

Best regards


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