Because virtualization becomes more and more common use and with Microsoft Hyper-V included in Windows Server at no additional costs and most server hardware nowadays is more than capable of running a physical Small Business Server (SBS) 2008 or 2011 installation and never get the full benefits of the hardware. It is worth considering to virtualize the SBS 2008 or 2011 server and run one or maybe two or more virtual servers beside it on the same hardware.
In this blog post I will put together some facts, tips and considerations you should look after before you start virtualizing a SBS 2008 or 2011 server. Of course a lot of this information can also be used for virtualizing non SBS servers.
Enable Hyper-V role on a SBS 2008 or 2011 server
So if you just want to add just one other server, why not install SBS 2008 or 2011 on the physical hardware and just enable the Hyper-V role?
The answer is really simple, because it is not supported!! Enabling the Hyper-V role on a SBS 2008 or 2011 server will break stuff, for some additional information read here: http://blogs.technet.com/b/sbs/archive/2009/08/07/you-cannot-install-the-hyper-v-role-on-the-sbs-2008-primary-server.aspx
So as we cannot enable the Hyper-V role on a SBS 2008 or 2011 server we need to install a Windows Server version on the physical hardware to function as a Host for the Virtual Machines. It is recommended that the Hyper-V Host will only hold the Hyper-V role and not to include any other roles or tasks. Only exception maybe for some management or backup tasks.
The Windows Server version we will choose is a real important decision, so let’s see what choices we have:
Hyper-V is included within Windows Server since version 2008 this was a version 1.0 and has a lot of limitations. I would not recommend using Windows Server 2008 to host the virtual machines. So I will limit to choice between the different server versions based on Windows Server 2008 R2 and Windows Server 2012.
SBS 2011 Premium Add-on
When you already bought SBS 2011, you might have bought the SBS 2011 Premium Add-on (PAO) in addition. The SBS 2011 PAO includes a Windows Server 2008 R2 standard and SQL 2008 R2 license. With Windows Server 2008 R2 Standard you have the right to install the software on a physical machine and install one Virtual Machine with the same license. This is called virtualization rights (1+1), you may do this only when you do not install any other role on the Host installation other than the Hyper-V role. When you install another role you will lose this right and need to buy a separate license for the virtual installation.
This said the SBS 2011 PAO will be a perfect consideration to use for your Host installation and run SBS 2011 and a second Virtual Machine for SQL server and / or a LOB application or even a Remote Desktop Session Host (Terminal) Server.
So the SBS 2011 PAO looks like an ideal solution, but one limitation is worth naming. Windows Server 2008 R2 standard has a 32GB memory limitation, this might be a problem when running SBS 2011 standard and also have a memory consuming SQL / LOB application. SBS 2011 standard itself with especially Exchange 2010 is a very memory consuming product, if you also need to run a loaded SQL / LOB application server beside this 32 GB might not be enough.
The Windows Server 2008 R2 Host installation needs about 2 – 4 GB, a SBS 2011 Standard for 25 – 50 users will need at least 20 – 24 GB, so this only leaves 6 – 10 GB for your SQL / LOB application server, this might be a problem. So keep this in mind if you are a growing organization and see the limit coming it is not possible to just insert more memory in your server, Windows Server 2008 R2 standard has a hard limit of 32 GB memory.
Windows Server 2008 R2 Enterprise or Datacenter
If memory could be an issue you might consider Windows Server 2008 R2 Enterprise or Datacenter, they both have a memory limit of 2 TB, this is a significant improvement. Also if you need to run more than one additional Virtual Machine you might consider both, Windows Server 2008 R2 Enterprise has an 1 to 4 virtualization right and Windows Server 2008 R2 Datacenter even 1 to unlimited. So with both version you will be far more flexible, but will cost considerably more than a standard or PAO version. Because also Windows Server 2012 is available at this moment I would not recommend these option only if you already own a license for these products it might be worth considering.
If you do not have the SBS 2011 PAO or already have a Windows Server 2008 R2 license the free Hyper-V server might be worth considering. The free Hyper-V Server is a stripped Windows Server version with only the Hyper-V role included, there aren’t any other roles included.
The Hyper-V Server 2008 R2 has a memory limit of 1 TB and the Hyper-V Server 2012 has even a memory limit of 4 TB. There are no limitations between the Hyper-V server and the full blown versions of Windows Server, only thing is there is no graphical user interface (gui) on the Hyper-V Server. There is a small configuration menu to do some basic tasks but furthermore you need to configure and administer the server via a command window or via a remote management console.
For additional information about the Hyper-V Server look here: http://technet.microsoft.com/en-us/library/hh923062.aspx
Windows Server 2012
If you are not comfortable with a non gui server or have no ability to remotely manage the server and also not have any license available the best option would be to go for a Windows Server 2012 edition. There are only 2 version applicable, the Standard and the Datacenter version, only difference between both versions are the Virtualization rights. Windows Server 2012 Standard has an 1 to 2 virtualization right and Datacenter even 1 to unlimited. Both version have a memory limit of 4 TB so no limitation anymore on the standard version.
Client Access Licenses
If you need one or two Virtual Machines beside the SBS 2008 or 2011 the Windows Server 2012 Standard is an ideal solution.
One thing to keep in mind is that when the Virtual Machines also are installed with Windows Server 2012, the SBS 2011 client access license (CALs) are not covered. SBS CALs cover for all servers in your SBS domain but up to the same version as is the base operating system (OS) of your SBS version. So with SBS 2008 this is Windows Server 2008 and for SBS 2011 this is Windows Server 2008 R2, if you install a newer version of Windows Server you need to buy separate CALs.
Enough considerations on which OS you could install on the physical hardware as Hyper-V Host. You have to keep in mind there is not one best choice available it all depends on your situation, do you already have licenses that can be used, are you comfortable using a server installation without a gui, how many Virtual Machines do you need to run, etc, etc. To make some choices easier here a little table with the different versions:
|Version||Memory Limit||Virtualization rights|
|Windows Server 2008 R2 Standard (SBS 2011 PAO)||32 GB||1 + 1|
|Windows Server 2008 R2 Enterprise||2 TB||1 + 4|
|Windows Server 2008 R2 Datacenter||2 TB||1 + unlimited|
|Hyper-V Server 2008 R2||1 TB||None|
|Hyper-V Server 2012||4 TB||None|
|Windows Server 2012 Standard||4 TB||1 + 2|
|Windows Server 2012 Datacenter||4 TB||1 + unlimited|
Because licensing is complex material I would recommend you contact your distributor or reseller if you have any doubt about the solution you would like to choose and verify if it fits your company.
If you want to read more about virtualization and licensing I would suggest reading this excellent post: http://www.aidanfinn.com/?p=13090
Let’s continue with some other considerations if you could or could not virtualize the SBS 2008 or 2011 server.
With SBS 2008 Microsoft introduced a wizard for configuring a backup, SBS Backup it is based on the Windows Backup but has its own configuration and monitoring options via the SBS console. It is easy to use and has no additional costs, you can configure backup to multiple disks, only thing is it only uses USB disks.
Problem is Hyper-V does not support USB redirection so you cannot attach the USB disks to a Virtual Machine and use them for SBS Backup. Of course there are some workarounds possible to attach an USB disk to a Virtual Machine, see this blog post http://blog.ronnypot.nl/?p=721 for some information, but this is probably not a supported workaround.
You can also create VHD files and attach them to the Virtual Machine and use them for SBS backup, but these VHD files are not attached and detached automatic and are not stored offline by default. You have to consider if this is a good alternative for you. Another option would be not using the wizards and interface but create command scripts using the command version (wbadmin.exe) of Windows Backup.
So if you want to use SBS Backup the way it is intended with USB disks, virtualization is not a good option.
As said there is no USB redirection with Hyper-V, this is for USB hard disks, but also for all other USB hardware, so no USB printers, scanners, drivers, dongles or what so ever.
As there is no USB redirection it also is not possible to redirect some other hardware like, Fax boards, other pci cards, hardware dongles, etc.
So if you have any specific hardware that needs to be connected to a Virtual Machine you have to make sure this is possible, but in most cases this might be a configuration where virtualization is not an option.
The question to virtualize or not to virtualize cannot be simply answered with just a true or false, it all depends on many factors, decisions and considerations. Hope the information given in this blog will help you making the decision if you would virtualize your SBS 2008 or 2011 server or not.