Configuring Live Migration & Cluster Shared Volume – Part 1

Why?

Microsoft Failover Cluster 2008 or Microsoft Cluster Services 2000 or 2003 are designed on the basis of Nothing Shared Architecture. Hence if we want to move the virtual machines from one cluster node to other cluster node we can’t do that. Because none of the Virtual Machine LUNs are shared between two cluster nodes at the same time. In this architecture complete LUN will get transferred in case of host dies & virtual machines can be restarted. But they can’t be migrated while they are up & running like vMotion.

New Hyper-V architecture was released with Windows 2008 R2 Server which supports shared volume between nodes. It called as Clustered shared volume. This volume can be used by all nodes at the same time. All virtual machines located in this LUN can be started on any of the host. If one node dies virtual machine will get started in any other available nodes. And can be live migrated (like vMotion) to other available nodes.

In this article we will be discussing how we can enable cluster shared volume & implement live migration to make our hyper-v cluster full proof. As we discussed above to implement Live Migration we need to have Clustered Shared Volumes i.e. CSV first we will configure CSV & then live migration.

Enable Cluster Shared Volume

Requirement:

1. Shared Disk Volume between cluster nodes. Make sure each node can mount this volume using cluster validation tool.
   
2. Dedicated Network for CSV communication traffic in case we have large number of virtual machines are running out of the cluster. Make sure you enable “Microsoft File & Print Sharing” & “Client for Microsoft Network” features on the CSV network card
   

Add a Shared Storage Volume as CSV

• Open Failover cluster manager. Right click the server name & click on Enable cluster shared Volumes
  

• Accept the supportability notice & click okay. Just to note CSV only supported in Hyper-v application & this volume only should contain virtual machine config & vhd files.
  

• Now you will able to see Cluster Storage Volume feature has been enabled in your failover cluster. However to make it work, we have to assign shared volume & a network adapter (optional)
  
• Right click the CSV & select Add Storage
  

• Select available storage volume & click okay
  

• Verify configuration clicking on cluster shared volumes.
  
• You can see this cluster storage disk has been mounted as a volume to C:\ClusterStorage\Volume1
  

• Use windows explorer & verify the same folder from all nodes. You should able to browse around the volume1 folder from both servers. If not check the event logs for any error. Here is one of them http://wp.me/phPxo-8C.

 

• Update Hyper-V configuration to use this LUN
  
• Open Hyper-V Manager Console, right click the server & go to Hyper-v settings. Update default virtual Disk & configuration location to C:\ClusterStorage\Volume1\
  

Add a Network Card for CSV Communication Traffic

• You can use Get-ClusterNetwork to see all used cluster network cards in this cluster
  
• If this cmdlet didn’t work you can use Import-Module Failover Clusters cmdlet to import power shell cmdlets.
  
• Out of box Private Network is always configured to use for primary CSV Traffic. However there are some caveats ;-), keep reading.
  

• Metric & AutoMetric attribute on each network card used to define or determine their participation in CSV Communication Network Traffic
  

• The Metric setting is used to determine the priority of the network. The network with the lowest value is the most preferred for CSV
  
• The AutoMetric setting identifies whether the Metric setting was set manually or automatically by the failover cluster. True means it is default
  

Change Values: ( Get-ClusterNetwork “Cluster Network 1” ).Metric = 1100

• The AutoMetric setting changes from True to False after you manually change the Metric setting. This is to prevent the failover cluster from automatically assigning a Metric setting. If you want the cluster to start automatically assigning the Metric setting again, change the AutoMetric setting back to True.