Enhanced (Failover) Placement of Virtual Machines on Windows 8 Hyper-V Cluster

Posted on April 6, 2012 by workinghardinit

One of the nice features in Windows 8 Hyper-V clustering are the “drain node” capability and the virtual machine priorities. You can see this in action in a video by Aidan Finn here.

For more details on draining a node see Draining Nodes for Planned Maintenance with Windows Server "8" for a detailed explanation.

Now another very important feature is the fact that the cluster is intelligent enough to determine what node is the best suited as a target during failover or live migration. Not only CPU and memory load of the hosts are taking into consideration but also the resource needs of the VM and the priority you have given those. This entire process is NUMA aware and as such with windows 8 can be evaluated on a per virtual machine basis. This means that you that the cluster will always try to get the best possible placement and thus performance for your virtual machines.

Now we also have affinity and anti affinity rules. Anti Affinity ensures that the nodes of a virtualized NLB farm will be placed on separate hosts to minimize risk. You don’t want one host to house all the nodes of you NLB farm!

On the other hand sometime you want virtual machines to stick together lets say you have an NLB farm but the virtual machines with the front end and middle tier need to stay together. In that case you use affinity rules to achieve this. On top of this the anti affinity rules will ensure that the NLB farm virtual machines are on different nodes.

Do note that when the cluster has to choose to break these rules versus bot being able to run the virtual machines it will choose to keep them running. It knows its priorities! Now if in such a situation there are not enough resource the priority will also come into play and the low priority machine may be shut down to ensure the higher priority ones can be up and running.

As you can imagine there are potentially a lot of factors/permutations at play here and I’m looking into doing some more test of these features and the intelligence in the process to see if we make the same decisions and how to best configure this for maximal performance & availability.

Learning Resources for Windows 8 Clustering, WNLB & Hyper-V 3.0

Posted on April 3, 2012 by workinghardinit

I know a lot of you are, just like me, actively investigating Windows 8 & Hyper-V. You’re downloading the Beta, reading blog post, discussing scenarios and use cases and that’s great. You’re investing in a bright future Smile

Here are some blog post that contain gems of information and that I’d like to bring to your attention:

Managing Hyper-V Replica from PowerShell => This is a very much discussed subject & with PowerShell you can automate the process & report on it’s status.
Welcome to Windows Server “8” Failover Clustering => Dynamic clusters & app health monitoring in the VM are really nice new features.
How to Enable Failover Clustering and Network Load Balancing PowerShell Help on Windows Server “8” => cluster.exe & nlb.exe are on the way out. PowerShell steps up to the plate
How to Enable CSV Cache => One of the innovations to enhance performance of CSV for read intensive IO (with write through cache for writes)
How to Create a Cluster in a Restrictive Active Directory Environment => here’s a great starting point for those of you who need to inter act with an separate AD team to get the clusters build.

Enjoy!

No Hyper-V Module for Windows PowerShell After Upgrading to Windows Server 8?

Posted on April 3, 2012 by workinghardinit

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 Smile

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 Smile

Happy scripting!

Upgrading Hyper-V Cluster Nodes to Windows Server 2012 (Beta) – Part 1

Posted on March 26, 2012 by workinghardinit

This is a multipart series based on some lab test & work I did.

Part 1 Upgrading Hyper-V Cluster Nodes to Windows Server 2012 (Beta) – Part 1
Part 2 Upgrading Hyper-V Cluster Nodes to Windows Server 2012 (Beta) – Part 2
Part 3 Upgrading Hyper-V Cluster Nodes to Windows 8 (Beta) – Part 3

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)”

So it looks for updates on line.

It didn’t find any but that’s OK.

Select the installation you want. I went with for Server with a GUI as I want screen shots. But as I wrote in the blog post Windows 8 Server With GUI, Minimal Server Interface & Server Core Lesson with the Desktop Experience Feature you can turn it into a Server Core Installation and back again now. So no regrets with any choice you make here, which is a nice improvement that can save us a lot of time.

Accept the EULA

We opt to upgrade (in production I go for a clean install)

I get notified that I have to remove PerfectDisk. I had an evaluation copy of Raxco PerfectDisk installed I used to do some testing with redirected CSV traffic and defragmentation (see Some Feedback On How to defrag a Hyper-V R2 Cluster Shared Volume).

So the upgrade was cancelled.

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 Smile 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 … Smile

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.

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My view on IT from the trenches

Category Archives: Windows 8