My colleague, Tim Jacobs, has published a good article covering virtual machine backups and VSS integration. In my opinion, VSS clearly is the way to go because the VMware sync driver or other proprietary solutions just don't cut it. Microsoft already included VSS support in Virtual Server 2005 R2 SP1 and also has it in Hyper-V.

Check out the article on his blog.

In the previous post, I talked about creating highly available virtual machines on Hyper-V and the fact that SCVMM can only create virtual machines on unused storage. The standard tools such as Hyper-V Manager and Failover Cluster Manager do support multiple virtual machines on the same volume (with a hotfix). So what happens to SCVMM in that case? Have a look at the screenshot below:

The virtual machines are in an unsupported configuration and cannot be managed from SCVMM (no starting, stopping etc...). This will probably be fixed in the final release but if you are testing the product now you know what to expect.

When you need to create a highly available virtual machine running on Microsoft's Hyper-V you need to do so on a Failover Cluster. In this post I will show you how to create a highly available virtual machine on a two-node Windows Server 2008 cluster. The cluster is using simple desktop machines with storage on an MSA2012i SAN (iSCSI).

There are two ways to create the virtual machine:

1. Use the Hyper-V Manager in conjunction with Failover Cluster Management.
2. Use System Center Virtual Machine Manager 2008 (SCVMM).

The first method is a bit clumsy because it involves two different consoles. That method, however, has more flexibility as you will see later. Let's take a look at the first method and see how you could create a virtual machine in the cluster on a shared volume.

Creating the virtual machine without SCVMM
Without SCVMM you need Hyper-V Manager and Failover Cluster Manager. To start, you need to have a volume available to the cluster. In my case, I had a volume with drive letter S: as available storage to the cluster as shown in the screenshot below.

Even a volume that is not part of a service or application (a resource group in old terminology) is owned by a particular host. In the screenshot you see that hyperv2 owns the disk.

The next step is to use Hyper-V Manager to create a virtual machine. It is important that you store both the virtual machine configuration and hard disk(s) on shared storage. To create the virtual machine, open Hyper-V Manager on the host that owns the disk and create a new virtual machine as shown below. This is the same as on a standalone host as this tool is not aware of the cluster.

A wizard will start to create the virtual machine. Just follow the wizard and make sure you use shared storage. We can now proceed to the next step and that is adding the machine to the cluster.

Now open Failover Cluster Management, right click Services and Applications and click Configure a Service or Application. A wizard will start. Follow the wizard until the screen below and select Virtual Machine (only available when Hyper-V is installed):

When you click Next, the wizard will enumerate the virtual machines on shared storage so that you can select them:

After the virtual machine has been selected, continue the wizard. The end result will be a new service called Virtual Machine with two resources (well, actually three): the virtual machine configuration, the virtual machine and the storage volume. The screenshot below illustrates what you see in the Failover Cluster Management console after running the wizard a few times to add other virtual machines on the same volume.

You can now start the virtual machine directly from Failover Cluster Management and install a guest operating system. If you need to attach an iso first, you will need to use Hyper-V Manager. The Failover Cluster Management tool provides an easy way to start Hyper-V Manager. Just right click the service (here called by default Virtual Machine).

From the moment the virtual machine is part of the cluster you will need to perform actions such as stopping, shutting down and saving state from Failover Cluster Management. If you use Hyper-V Manager to stop the virtual machine for example, the cluster will restart the virtual machine again (with the default resource settings).

Creating the virtual machine with SCVMM
SCVMM, being the 'single pane of glass' for virtualization management provides a way to create new virtual machines on both clusters and standalone Hyper-V hosts. Before you can create a virtual machine on a cluster you need to add the cluster to SCVMM. From the Actions pane, select Add Host as shown below:

In the Add Hosts wizard, type the cluster name in Host server name and press Enter. The cluster should be added to the list as shown below:

Now continue the wizard to deploy the SCVMM agent on each node in the cluster (=automatic). The cluster will be shown in SCVMM as shown below:

Adding a virtual machine is easy but the current beta of SCVMM has some limitations:

• SCVMM only supports one virtual machine per cluster volume. This effectively means I need one LUN per virtual machine, something I need anyway if I want to 'Quick Migrate' individual virtual machines.
• SCVMM only supports volumes with drive letters (no mount points).

Before you create the virtual machine, make sure there is available storage in the cluster that is not used by any other virtual machine. To create the virtual machine, just select New Virtual Machine from the Actions pane at the right to launch the wizard. The wizard is straightforward but you should not forget to configure the virtual machine as highly available. You do so from the Configure Hardware dialog in the wizard. Scroll to the bottom where there is an Availability section. When the wizard is finished, SCVMM will have created a new service in the cluster called SCVMM vmname Resources. You can now start the virtual machine from SCVMM and start installing a guest operating system.

Conclusion
Creating a highly available virtual machine is easy but as you have seen, there are several ways to do it. There are also some discrepancies between what you can do with and without SCVMM. The final version of SCVMM will have to solve this so that you can truly use it as your primary management tool for Hyper-V.

REMARK: I my setup I installed the following hotfix: http://support.microsoft.com/?id=951308. This hotfix provides more functionality and virtual machine control for Hyper-V in a failover cluster.

I got my hands on an HP MSA2012i and thought I'd share some of the configuration screens with you. Part of the HP StorageWorks 2000 Modular Smart Array family, this particular model is the iSCSI model with one controller (it is not meant for production so we did not need the 2nd controller). The MSA2012i has twelve SAS drive bays for 3.5 inch disks and we filled it with 146GB 15K disks. There are two other models: one fibre channel and one SAS.

Each controller has three ethernet ports, one for management and two for data access. I connected the management port to our network and pointed my browser to the IP address assigned by our DHCP server. After logging in with username manage and password !manage (defaults) the configuration can start.

The first thing to do is to configure the ethernet ports. To configure the data ports, go to General Config and then host port configuration:

The addresses above (port 0 and port 1) are used for the iSCSI discovery process and of course disk access as well. In the Microsoft iSCSI initiator for example, you would set one of these (or both) in the Discovery tab:

The MSA2000 works with the concept of vdisks and volumes. A vdisk is nothing more than a collection of physical disks configured with some protection level (RAID5, RAID10, ...) and optional spare disk(s). There are two ways to create a vdisk:

1. Automatic virtual disk creation (policy-based)
2. Manual virtual disk creation (detail-based)

The policy-based method just asks you for a fault tolerance level (none=RAID0, medium=RAID5 or high=RAID50), the size of the vdisk in GB and the number of volumes to create in the vdisk.

I will show manual disk creation to create a vdisk with 11 disks and one spare (no best practice or anything, just demo). The first screen asks for the vdisk name and the RAID level (RAID0, 1, 3, 5, 6, 10, 50):

The second screen asks for the disks and whether or not you want spare drives:

The third screen asks for the spare disk(s):

After clicking continue, a summary is shown with a button to create the vdisk:

After clicking Create Virtual Disk, the vdisk will be created and initialized. Initialization can take a long time but during that time volumes can already be created and used.

The next thing to do is to create volumes. Let's create a 100GB volume on the vdisk we just created. From the Volume Management section at the left there is the add volume option. In the screenshot below, a volume of 100GB is created without assigning a LUN number. When you assign a LUN number you present the LUN globally. If you do not want that you set LUN to NONE and assign the volume to a host from the volume mapping link.

After clicking Add Volume the volume is shown in the volume map of the vdisk:

To map the volume to a host:

Of course, hosts don't just magically appear in the above list. You can add hosts manually (there is a link somewhere in the menu at the left) or make them appear by using the iSCSI initiator on the host to connect to the MSA target. When the volume is mapped to the host it will appear if the iSCSI initiator was configured correctly:

As you can see, configuration is very simple although not as easy as an Equallogic box, a reference for configuration simplicity. I did notice one bug though and that is the fact that every other vdisk is owned by the second (in our case, non existent) controller. This might be solved by a more recent firmware though.