Now and then you have a need to expand a LUN when running enterprise systems. This is a trivial action in most cases because you simply add physical drives to the array and then use Disk Management to extend the drive to encompassthe newly expanded volume.  Unfortunately, on highly-available systems such as those running Failover Clustering with Cluster Shared Volumes (CSV)-enabled features the drive is reserved and un-manageable by Disk Management. The traditional methods of extending the size of a drive isn’t capable of being used due to the tools (Disk Management)disabling the functionality.

 

Most of users don’t know how to extend CSVwhen their VHD is out of space. Though some users understand they should connect to CSV owner server to extend the CSV, but maybe you are not sure if this operation will cause the VM to go offline, they want this operation allow the currentworkloads to current running during the extend process.

 

There is an blog article post to Technet on July describing how to extend CSV. It gives four steps to extend CSV. As writer said, this procedure is possible and capable of being done without any loss of service to client services such as virtual machines.

 

Blog article link:

http://blogs.technet.com/b/chrad/archive/2010/07/15/cluster-shared-volumes-csv-extending-a-volume.aspx