I was working on a little project for a company that was running TS Gateway on 32bit Windows 2008. The reason they did not go for x64 at the time was that they used Virtual Server as their virtualization platform for some years and not Hyper-V. One of the drawbacks was that they could not use x64 guest VMs. Since then they have move to Hyper-V and now also run Window Server 2012. So after more than 5 years of service and to make sure they did not keep relying on aging technology it is time to move to Windows Server 2012 RD Gateway and reap the benefits of the latest OS.
All in all the Microsoft documentation is not too bad, all be it that the information is a bit distributed as you need to use various tools to complete the process. Basically, depending on the original setup of the source server you’ll need to use the TS/RD Gateway Export & Import functionality, Web Deploy (we’re at version 3.0 at the time of writing) and the Windows Server Migration Tools that were introduced with Windows 2008 R2 and are also available in Windows Server 2012.
In a number of posts I’ll be discussing some of the steps we took. You are reading the second post.
Installing & using the Windows Server Migration Tools To Migrate Local Users & Groups
TS/RD Gateway Export & Import (Fixing Event ID 2002 “The policy and configuration settings could not be imported to the RD Gateway server "%1"" because they are associated with local computer groups on another RD Gateway server”)
As discussed in the first part we need to migrate some local users & groups on the TS Gateway (source) server as they are also being used for some special cases of remote access, next to Active Directory users & groups for the Remote Access Policies (RAPs) & Connection Authorization Policies (CAPs). The tool the use is the Windows Server Migration Tools. These were introduced with Windows 2008 R2 and are also available in Windows Server 2012.
Some people seem to get confused a bit about the installation of the Server Migration Tools but it’s not that hard. I have used these tools several times before in the past and they work very well. You just need to read up a bit on the the deployment part and once you have it figured out they work very well.
Installing the Windows Server Migration Tools on the DESTINATION Server
First we have to install the on the DESTINATION host (W2K12 in our case, the server to which you are migrating)). For this we launch Server Manager and on the dashboard select Manage and choose Add Roles & Feature.
Navigate through the wizard until you get to Features. Find and select Windows Server Migration Tools. Click Next.
Click Install to kick of the installation.
After a while your patience will be rewarded.
Installing the Windows Server Migration Tools on the SOURCE Server
To install the Windows Server Migration Tools on the SOURCE server, you need to run the appropriate PowerShell command on the DESTINATION server. This is what trips people up a lot of the time. You deploy the correct version of the tools from the destination server to the source server, where you will than register them for use. Do this with an admin account that has admin privileges on both the DESTINATION & SOURCE Computer.
Start up the Windows Server Migration Tools from Server Manager, Tools.
This launches the Windows Server Migration Tools PowerShell window.
Our SOURCE server here is the32 bit (X86) Windows 2008 TS Gateway Server. The documentation tells us the correct values to use for the parameters /architecture and /OS to use.
Now before you run this command be sure to go to the ServerMigrationTools folder as the UI fails to do that for you.
Also this is PowerShell so use .\ in front of the command otherwise you’ll get the error below.
While you want this:
Now you have also deployed the correct tools to the SOURCE server, our old legacy TS Gateway Server. Next we need to register these tools on the SOURCE Server to be able to use them. You might have gotten the message already you need PowerShell deployed on the SOURCE Serveras documented.
If you have PowerShell, launch the console with elevated permissions (Runs As Administrator) and run the following command: .\SmigDeploy.exe
Congratulations you are now ready to use the Windows Server Migration Tools! That wasn’t so hard was it?
Using the Windows Server Migration Tools To Migrate Local Users & Groups
To export the local users and groups from the source TS/RD Gateway server you start up the Windows Server Migration Tools on the SOURCE server (see the documentation for all ways to achieve this) and run the following PowerShell command: Export-SmigServerSetting -User All -Group –Path C:\SysAdmin\ExportMigUsersGroups –Verbose
As you can see I elected to migrate all user accounts not just the enabled or disabled ones. We’ll sort those out later. Also note the command will create the folder for you.
To import the local users and groups to the target RD Gateway server you start up the Windows Server Migration Tools on the Destination server (see the documentation) , i.e. our new Windows Server 2012 RD Gateway VM.
Do note that the migrated user accounts will be disabled and have their properties set to "Next Logon". This means you will have to deal with this accordingly depending on the scenarios and communicate new passwords & action to take to the users.
Do note that the local groups have had the local or domain groups/users added by the import command. Pretty neat.
You’re now ready for the next step. But that’s for another blog post.
As after installing http://support.microsoft.com/kb/2770917 on Windows Server 2012 Hyper-V hosts the integration services components are upgraded from 6.2.9200.16384 to 6.2.9200.16433. Windows Server 2012 guest get that same upgrade and as such also the newer integration services components. The guest with older OS version needed a different approach. So I turned to all the great PowerShell support now available for Hyper-V to automate this. Pretty pleased with the results of our adventures in PowerShell scripting I let the script go on Hyper-V cluster dedicated to test & development. As such there are some virtual machines on there running Windows 2003 SP2 (X64) and Windows XP SP3 (x86). Guess what, after running my script and verifying the integration services version I see that those VM still report version 6.2.9200.16384 . No update. Didn’t my new scripting achievement “take” on those older guests?
So I try the install manually and this is what I get:
Why is there no upgrade for these guests? Are they not needed or do I have an issue? So I mount the ISO and dig around in the files to find a clue in the date:
It looks like there are indeed no update components in there for Windows XP/ W2K3. So then I look at the following registry key on the host where I normally use the Microsoft-Hyper-V-Guest-Installer-Win6x-Package value to find out what integration services version my hosts are running:
Bingo, there it seems indicated that we indeed need version for XP/W2K3 and version for W2K8(R2)/W2K12 and Vista/Windows 7/Windows 8. Cool, but I had to check if this was indeed as it should be and I’m happy to confirm all is well. Ben Armstrong (http://blogs.msdn.com/b/virtual_pc_guy/) confirmed that this is how it should be. There was a update needed for backup that only applied to Windows 8 / Windows Server 2012 guests. As this fix was in a common component for Windows Server 2008 and later they all got the update. But for the older OS versions this was not the case and hence no update is need. Which is reflected in all the above. In short, this means your XP SP3 & W2K3SP2 VMs are just fine running the version of the integration services and are not in any kind of trouble.
This does leave me with an another task. I was planning to do enhancements to my script like feedback on progress, some logging, some better logic for clustered and non clustered environments, but now I have to also address this possibility and verify using the registry keys on the host which IC version I should check against per OS version. Checking against just for the one related to the host isn’t good enough .
Making a million IOPS possible in a Windows Server 2012 Hyper-V VM
A lot of you will have seen the demos of a Hyper-V guest with VHDX disks running on Windows Server 2012 doing a million apps, if you haven’t yet, take a look here. While some quickly dismissed this as “irrelevant boasting” without real life relevance, I respectfully disagree. This is smart future proofing by Microsoft and provides a hypervisor ready for the future hardware capabilities and capable to handle the most demanding workloads today & in the years to come. Sure such a demo is under lab/ideal conditions and does not reflect the majority of real life environments but it’s nice to see what a hypervisor is capable of if and when you might need it. Remember there was a day that 4GB was a lot of RAM and 2TB sounded gigantic. Also remember that some people have larger needs than others. Until Windows Server 2008 R2 you had some limitations in storage IO performance that would not allow for a million IOPS. These had to be addressed or all the efforts with regards to capabilities and performance in regard to storage, CPU, networking and memory would just hit those particular bottlenecks. So it is addressing real needs and indeed also smart future proofing.
Capabilities of virtual machine storage IO throughput in Windows 2008 R2
The capabilities listed below dictate the IO capabilities in virtual machines running on Windows Server 2008 R2 Hyper-V:
Limited to one IO channel per virtual SCSI Controller
256 queue depth/SCSI for all devices attached to that SCSI adapter.
There was one fixed vCPU (0) dedicated to handling IO.
The picture above illustrates these limits. You see two virtual SCSI Controllers each having 2 VHD virtual disks attached. Each disk shares the one channel the controller it is attached to has.
These limits could become a bottle neck but that was never was too big of a problem with a maximum of 4 vCPUs in Windows 2008 R2 Hyper-V. If needed for performance we might have attached VHDs to different virtual SCSI controllers for the best possible performance in Windows Server 2008 R2 Hyper-V .
With 64 vCPUs and ever more demanding workloads these limitations would become a (serious) issue so this needed to be addressed. If not, despite all other efforts in regards to the 4 big resources (memory, storage and network) in Windows 2012, this would remain the limiting factor of IOPS inside a virtual machine on Windows 2012.
Windows Server 2012 improvements to virtual machine storage IO scaling
The picture above illustrates the improvements in Windows Server 2012 Hyper-V IO Scaling:
There is now 1 channel per 16 vCPUs, per virtual SCSI device, per controller. So that means you have 4 channels, per VHDX attached to a virtual SCSI Controller when you have 64 vCPUs in the virtual machine. Compared to before, this is a significant improvement and a much needed one with the 64 vCPUs capability there is now.
IO interrupt handling is now distributed amongst all vCPUs and this process is NUMA aware. This is a huge improvement!
There is now a 256 queue depth/device attached to a specific SCSI adapter. That’s another big improvement.
That people, is how you get a virtual machine to handle a million IOPS. Nice! The questions or doubts whether Hyper-V can deliver the capacity, throughput & performance have been wiped of the table, yes also for virtual storage IOPS. You can now go straight to how it will address your business needs. From my experience it does so brilliantly and very cost effectively. Life might not be perfect but it is very good
At the end of this day I was doing some basic IO tests on some LUNs on one of the new Compellent SANs. It’s amazing what 10 SSDs can achieve … We can still beat them in certain scenarios but it takes 15 times more disks. But that’s not what this blog is about. This is about goofing off after 20:00 following another long day in another very long week, it’s about kicking the tires of Windows and the SAN now that we can.
For fun I created a 300TB LUN on a DELL Compellent, thin provisioned off cause, I only have 250 TB
I then mounted it to a Windows 2008 R2 test server.
The documented limit of a Volume in Windows 2008 R2 is 256TB when you use 64K allocation size. So I tested this limit by trying to format the entire LUN and create a 300TB simple volume. I brought it online, initialized it to an GPT disk, created a simple volume with an allocation unit size of 64K and well that failed with following error:
There is nothing unexpected about this. This has to do with the maximum NTFS volume size supported on a GPT disk. It
depends on the cluster size that is selected at the time of formatting. NTFS is currently limited to 2^32-1 allocation units. This yields a 256TB volume, using 64k clusters. However, this has only been tested to 16TB, or 17,592,186,040,320 bytes, using 4K cluster size. You can read up on this in Frequently asked questions about the GUID Partitioning Table disk architecture. The table below shows the NTFS limits based on cluster size.
This was the first time I had the opportunity to test these limits I formatted part of that LUN to a size close to the limit and than formatted the remainder to a second simple volume.
I still need get a Windows Server 2012 test server hooked up to the SAN. To see if anything has changed there. One thing is for sure, you could put at least 3 64TB VHDX files on a single volume in Windows. Not too shabby . It’s more than enough to put just about any backup software into problems. Be warned, MSFT tested and guarantees performance & behavior up to 64TB in Windows Server 2012, but beyond that you’d better do your own due diligence.
The next thing I’ll do when I have a Windows Server 2012 host hooked up is, is create 64TB VHDX file and see if I can go beyond it before things break. Why, well because I can and I want to take the new SAN and Windows 2012 for a ride to see what boundaries we can push. The SANs are just being set up so now is the time to do some testing.
A lot of us who build failover clusters are bound to run into the fact that the node names as shown the Failover Cluster Management GUI is not always consistent in the names format it gives to the nodes. Sometimes they are lower case, sometimes they are upper case. See the example below of a Windows Server 2008 R2 SP1 cluster.
Many a system administrator has some slight neurotic tendencies. And he or she can’t stand this. I’ve seen people do crazy things like trying to fix this up to renaming a node in the registry. Do NOT do that. You’ll break that host. People check whether the computer object in AD is lower or upper case, whether the host name is lower or upper case, check how the node are registered in DNS etc. They try to keep ‘m all in sync at sometimes high cost But in the end you can never be sure that all nodes will have the same case using the GUI.
So what can you do?
Use cluster.exe to add the node to the cluster. That enforces the case you type in the name! An example of this is when you’d like upper case node names:
Some claim that when you add all nodes at the same time and they will all be the same. But ‘m not to sure this will always work.
In Windows 2012 PowerShell replaces cluster.exe (it is still there, for backward compatibility but for how long?) and they don’t seem to enforce the case of the names of the node. For more info on Failover Clustering PowerShell look at Failover Clusters Cmdlets in Windows PowerShell, it’s a good starting point.
Don’t despair my fellow IT Pros. Learn to accept that fail over clustering is case insensitive and you’ll never run into any issue. Let it go …. Well unless you get a GUI bug like we had with Exchange 2010 SP1 or any other kind of bug that has issues with the case of the nodes .
If you want to use cluster.exe (or MSClus) for that matter you’ll need to add it via the Add Roles and Features Wizard / Remote Administration Tools /Feature Administration Tools / Failover Clustering Tools. Note that there are not present by default.
On an upgraded node I needed to uninstall failover clustering and reinstall it to get it to works, so even in that scenario they are gone and I needed to add them again.
MSClus and Cluster.EXE support Windows Server 2012, Windows 2008 R2 and Windows 2008 clusters. The Windows Server 2012 PowerShell module for clustering supports Windows Server 2012 and Windows Server 2008 R2, not Windows Server 2008.
When I upgraded some of my Hyper-V hosts from Windows 2008 R2 to Windows 8 I noticed I wanted to do some experiments using the Hyper-v Module for Windows PowerShell. So the first thing I did was install the Windows PowerShell integrated Scripting Environment (ISE) via the Add Roles and Features Wizard on my client. You don’t usually install this on your servers.
We opted to restart automatically if required, so we get a warning this server might restart.
Windows PowerShell ISE is installing
We are informed of our successful installation.
That was easy and no reboot required. So we launch ISE and start testing some commands of our new Hyper-V Module. But that doesn’t do much for us. Nothing happens.
So I try some more commands. But no luck, just some errors that the commands are not recognized or Get-Help can’t find anything of that command. I also not that for non of the Hyper-V commands I have any IntelliSense support.
So it seams the Hyper-V Module for Windows PowerShell is not installed. But I can’t make that out from the Roles Wizard.
I needed to get this going fast so I uninstalled the Hyper-V role and than added it again. That did the trick as now the Hyper-V Module for Windows PowerShell is also installed because I can execute commands
Just install the Hyper-V Module for Windows PowerShell via Features
But after discussing this with Microsoft it turns out that uninstalling and reinstalling the Hyper-V role is not necessary at all. You see when you upgrade a Window 2008 R2 node to Windows 8 it does not install Hyper-V by default as this would change the original install base and they try not to install features you didn’t have before during an upgrade. On a clean install where you add the Hyper-V role you won’t have this issue as the Hyper-V Module for Windows PowerShell is installed by default. What confused me is that I didn’t see an option under Roles to add Role Services to roles as I was used to do in Windows 2008 R2. There is no sub tree or anything.
I was thinking along the same path in Windows 8 but here we can find it in the in “Add Roles and Features Wizard” under Features / Remote Server Administration Tools sub tree. That has two entries. One for Feature Administration Tools and one for Role Administration tools and und the latter we find the Hyper-V Management Tools with Hyper-V Module for Windows PowerShell. Just a tip
You can add it your self after the upgrade by going to Server Manager and starting the Add Roles & Features Wizard.
You go through the normal steps and select to install Hyper-V Module for Windows PowerShell.
We are asked for confirmation of our request actions.
The Hyper-V Module for Windows PowerShell is being installed.
And we have a successful install. We can start scripting on that node right way
After I got back from the MVP Summit 2012 in Bellevue/Redmond I could wait to start playing with a Windows 8 Hyper-V cluster so I decided to upgrade my Windows 2008 R2 cluster nodes to Windows 8. That means evicting them on by one, upgrading them and adding them to a new Windows 8 cluster. As we can build a one node cluster this can be done a node at the time. This isn’t a fail proof definite “How To”, I’m just sharing what I did.
Evicting a node
Before evicting a node make sure all virtual machines are running on the other node(s). As you can see the cluster warrior has 2 nodes, crusader & saracen (I was listening to some Saxon heavy metal at the time I built that lab setup). We evacuated node saracen prior to evicting it.
Evict the node & confirm when asked.
When this is done all storage is off line to the node evicted from the cluster. No need to worry about that.
Upgrade that node to Windows 8
To anyone having installed/upgraded to Windows 2008 R2 this should all be a very recognizable experience. Being lazy, I left the iSCSI initiator configuration in there with the Hyper-V & failover cluster roles installed during the upgrade. Now for production environments I like to build my nodes from scratch to have an exactly known, new and clean installation base. But for my test lab at home I wanted to get it done as fast as possible. If only the days had more hours …For extra safety you can pull the plug (or disable the switch ports) on your iSCSI or FC connections and make sure no storage is presented to the node during the upgrade process. Now please do mind is use Intel server grade NIC adaptors for which Windows 8 beta has drivers. Your situation may vary so I can’t guarantee the 7 year old FC HBA in your lab server will just work, OK!?
So run setup.exe from the Windows 8 (Beta) ISO you extracted to a folder on the server or from the (bootable) USB you created with the downloaded ISO.
The Windows Setup installer will start.
Click on “Install now” to proceed and start the setup process.
Select to “Go online to get the latest updates for Setup (Recommended)”
I uninstalled PerfectDisk but still it was a no go. I had to remove all traces of it in the registry & files systems that the uninstall left or the upgrade just wouldn’t start. But after that it worked.
That means we can kick of the upgrade! It all looks very familiar It takes a couple of reboots and some patience. But all in all it’s a fast process.
After this step it takes a couple of reboots and some patience. But all in all it’s a fast process. After some reboots and a screen that goes dark in between those …we get our restyled beta fish.
And voila we’re where we need to be …
After the upgrade process I ran into one error. The GUI for Failover Clustering would not start. The solution if found for that was simply to remove that role and add it again. That did the trick.
So this was a description of the first steps to transition a Windows 2008 R2 SP1 cluster to a Windows 8 (Beta) Cluster. As seen we evict the nodes one by one to upgrade them or do a clean install. In the latter case you’ll need to do the iSCSI initiator configuration again, install the Failover Cluster role and in the case of a Hyper-V cluster the Hyper-V role. The nodes can than be added to a new Windows 8 cluster, starting out with a one node cluster. More on that in the second part of this blog post.
As I mentioned in an introduction post Thinking About Windows 8 Server & Hyper-V 3.0 Network Performance there will be a lot of options and design decisions to be made in the networking area, especially with Hyper-V 3.0. When we’ll be discussing DVMQ (see DMVQ In Windows 8 Hyper-V), SR-IOV in Windows 8 (or VMQ/VMDq in Windows 2008 R2) and other network features with their benefits, drawbacks and requirements it helps to know what Receive Side Scaling (RSS) is. Chances are you know it better than the other mentioned optimizations. After all it’s been around longer than VMQ or SR-IOV and it’s beneficial to other workloads than virtualization. So even if you’re a “hardware only for my servers” die hard kind of person you can already be familiar with it. Perhaps you even "dislike” it because when the Scalable Networking Pack came out for Windows 2003 it wasn’t such a trouble free & happy experience. This was due to incompatibilities with a lot of the NIC drivers and it wasn’t fixed very fast. This means the internet is loaded with posts on how to disable RSS & the offload settings on which it depends. This was done to get stability or performance back for application servers like Exchange and others applications or services.
The Case for RSS
But since Windows 2008 these days are over. RSS is a great technology that gets you a lot better usage of out of your network bandwidth and your server. Not using RSS means that you’ll buy extra servers to handle the same workload. That wastes both energy and money. So how does RSS achieve this? Well without RSS all the interrupt from a NIC go to the same CPU/Core in multicore processors (Core 0). In Task Manager that looks not unlike the picture below:
Now for a while the increase in CPU power kept the negative effects at bay for a lot of us in the 1Gbps era. But now, with 10Gbps becoming more common every day, that’s no longer the case. That core will become the bottle neck as that poor logical CPU will be running at 100%, processing as much network interrupts in can handle, while the other logical CPU only have to deal with the other workloads. You might never see more than 3.5Gbps of bandwidth being used if you don’t use RSS. The CPU core just can’t keep up. When you use RSS the processing of those interrupts is distributed across al cores.
With Windows 2008 and Windows 2008 R2 and Windows 8 RSS is enabled by default in the operating system. Your NIC needs to support it and in that case you’ll be able to disable or enable it. Often you’ll get some advanced features (illustrated below) with the better NICs on the market. You’ll be able to set the base processor, the number of processors to use, the number of queues etc. That way you can divide the cores up amongst multiple NICs and/or tie NICs to specific cores.
So you can get fancy if needed and tweak the settings if needed for multi NIC systems. You can experiment with the best setting for your needs, follow the vendors defaults (Intel for example has different workload profiles for their NICs) or read up on what particular applications require for best performance.
If you notice that RSS is correctly configured but it doesn’t seem to work for you it’ might be time to check up on the other adaptor offloads like TCP Checksum Offload, Large Send Offload etc. These also get turned of a lot when trouble shooting performance or reliability issues but RSS depends on them to work. If turned off, this could be the reason RSS is not working for you..
I already mentioned that during the Experts2Experts Virtualization Conference I met a lot of great people and I presented on High Performance & High Availability networking for Hyper-V clusters (10Gbps goodness). Some of the people I met I already knew from the on line community and others were unknown to me until that event. Among the attendees we found some of the usual virtualization suspects in our community like Aidan Finn, Jeff Wouters, Carsten Rachfahl, Ronnie Isherwood.
Now Carsten Rachfahl is a MVP in Virtual Machine expertise but he’s also a dynamic entrepreneur who shows a lot of initiative. Using social media he is really making in effort to get people & customers to notice important snippets of information by providing easy and fast access to them. He’s very active as a speaker, on Twitter and on his blogs. On top of that he does podcasts and video interviews. For Hyper-V information go to http://www.hyper-v-server.de/ which you can also use as an entry point for his other sites focusing on several aspects of IT in the Microsoft sphere in Germany. Like cloud computing & Licensing. There you’ll also find the videos of interviews on these subjects. It’s quite an impressive endeavor.
Carsten took the opportunity to make some videos with all the above suspects on various subject and he recently released our interview.
In this video we continued the discussion that Aidan started on CSV and we briefly touched on a subject you could make hour long documentaries about: storage options in Windows Hyper-V now and in the years to come. Enjoy!
When an environment evolves (growth, mergers, different needs) you have might very well have resource needs above and beyond the limits of the original Windows edition that was installed. Scaling out might not the right (or possible) solution you so scale up is alternative option. Today with Windows Server 2008 R2 this is very easy. However, again and again I see people resorting labor intensive and often tedious solutions. Some go the whole 9 yards and do a complete clean install and migration. Others get creative and do a custom install with the windows media to achieve an in place upgrade. But all this isn’t needed at all. Using DISM (Windows Edition-Servicing Command-Line Options) you can achieve anything you need and every role, feature, app on your server will remain in good working condition. Recently I had to upgrade some standard edition Hyper-V guest servers to the enterprise edition to make use of more than 32 GB of RAM. Another reason might be to move from Windows Server 2008 R2 Enterprise Edition to Data Center Edition for hyper-v host to make use of that specific licensing model for virtual machines.
Please note the following:
You can only do upgrades. You CANNOT downgrade
The server you upgrade cannot be a domain controller (demote, upgrade, promote)
This works on Standard, Enterprise edition, both full & core installations.
You cannot switch form core to full or vice versa. It’s edition upgrade only, not for switching type of install.
This is how to find the possible target editions for your server:
C:\Windows\system32>DISM /online /Get-TargetEditions
Deployment Image Servicing and Management tool
Image Version: 6.1.7600.16385
Editions that can be upgraded to:
Target Edition : ServerDataCenter
Target Edition : ServerEnterprise
The operation completed successfully.
So I went to Enterprise Edition by executing this process takes some time but is painless but for one reboot.
C:\Windows\system32>Dism /online /Set-Edition:ServerEnterprise/ProductKey:489J6-VHDMP-X63PK-3K798-CPX3Y
Deployment Image Servicing and Management tool
Image Version: 6.1.7600.16385
Starting to update components...
Starting to install product key...
Finished installing product key.
Removing package Microsoft-Windows-ServerStandardEdition~31bf3856ad364e35~amd64~~6.1.7601.17514
Finished updating components.
Starting to apply edition-specific settings...
Restart Windows to complete this operation.Do you want to restart the computer now (Y/N)?
You either use a MAK key (if you don’t have a KMS server) or the default key for your volume license media. When you have KMS in place (and the matching server group KMS key A, B, or C) the activation will be done automatically and transparent for you. Standard trouble shooting applies if you run into an issue there.
These are the public keys for use with a KMS server:
Windows 7 Professional – FJ82H-XT6CR-J8D7P-XQJJ2-GPDD4
Windows 7 Professional N – MRPKT-YTG23-K7D7T-X2JMM-QY7MG
Windows 7 Enterprise – 33PXH-7Y6KF-2VJC9-XBBR8-HVTHH
Windows 7 Enterprise N – YDRBP-3D83W-TY26F-D46B2-XCKRJ
Windows 7 Enterprise E – C29WB-22CC8-VJ326-GHFJW-H9DH4
Windows Server 2008 R2 HPC Edition – FKJQ8-TMCVP-FRMR7-4WR42-3JCD7
Windows Server 2008 R2 Datacenter – 74YFP-3QFB3-KQT8W-PMXWJ-7M648
Windows Server 2008 R2 Enterprise – 489J6-VHDMP-X63PK-3K798-CPX3Y
Windows Server 2008 R2 for Itanium-Based Systems – GT63C-RJFQ3-4GMB6-BRFB9-CB83V
Windows Server 2008 R2 Standard – YC6KT-GKW9T-YTKYR-T4X34-R7VHC
Windows Web Server 2008 R2 – 6TPJF-RBVHG-WBW2R-86QPH-6RTM4
Don’t worry this is public information (KMS Client Setup Keys), these will only activate if you have a KMS server and the to key make that KMS server work.
Either way there is no need for reinstall & migration or upgrade installation in for a simple upgrade scenario So do your self a favor and always check if you can use DSIM to achieve your goals!