In some smaller organisations virtual machines (VM) often run on local storage DAS – Direct Attached Storage on the hosts whereas in bigger businesses many if not all production VMs are hosted on shared storage (e.g. a SAN) , so the virtual machine executes on a given host but the virtual hard disk and VM metadata resides elsewhere. In either case there might be times where you would want to move the storage for a virtual machine but leave it running on its current host. For example you might want to move a virtual machine from DAS to a SAN as it becomes more critical to a business, or you are upgrading or replacing a SAN. This is no a simple process in Windows Server 2012 and you can leave the machine running while you do it as you can see in this short screencast..
where my poor SQL Server 2012 VM gets moved around my demo rig while running a complex query again and again.
Things to note:
This screencast moves the VM to a highly availability file share, which I created in an earlier post in this series. Note that that file share is specifically designed to host running VMs using the new SMB 3 capabilities in Windows Server 2012, and configured to do so as opposed to storing conventional files or to run as an NFS file share.
Permissions to that share are granted to the hosts running hyper-V in my case I created a group called Hyper-V Servers to put my hosts in and assigned permissions to that.