One of the great new features coming in Windows Server 2012 is Storage Migration for Hyper-V. Storage Migration allows an administrator to relocate the source files that make up a virtual machine to another location without any downtime.
In the last post, part 2, I covered Live Migration, a feature introduced in Windows Server 2008 R2, and further enhanced in Windows Server 2012. I also covered a few of the new features added for virtual network adapters.
Similar to Live Migration, Storage Migration creates a copy of the file or files at the new location. Once that is finished, Server 2012 does a final replication of changes and then the virtual machine uses the files in the new location.
With proper planning, the Storage Migration feature probably won’t be needed very often. However; as you may well know, once servers go live, things change. With disk space continuing to get cheaper every day, corporations and organizations are keeping more and more data. This is often one of the reasons relocation of large virtual disks is needed.
Storage Migration comes in a couple different flavors but essentially accomplishes the same both ways.
First, let’s take a look at a single Hyper-V host environment where we want to move the virtual machine files to another disk.
Select new location and screenshot of VM post migration no down time
First we open Hyper-V Manager from the Start Menu or the Tools menu in Server Manager. In the center pane, right-click a virtual machine and select Move. Or select the VM and click Move in the right pane. The wizard will run with a basic description of what it does and whether or not you want to see the first screen again. The second page asks if we want to move the entire virtual machine or just the storage. Once we’ve selected our move option, we will choose which storage to move.
Select items to move
We can move all to a single location, move different files to different locations, or move only the virtual hard disks.
Select new location and screenshot of VM during migration
In the final screen, we select the new location and click Finish. Hyper-V Manager will display the status of the Storage move.
During this entire process, the virtual machine remains available and responsive. Once the move is finished, we can see that the Virtual hard disk, Snapshot File Location, and Smart Paging File Location settings reflect the new file locations.
Second, let’s see the feature in action in a clustered VM environment with two hosts. The feature looks a little different in a cluster because we will instead be using Failover Cluster Manager.
Storage Migration in Failover Cluster Manager
In Failover Cluster Manager, click Roles. In the main pane, right-click a virtual machine, hover Move, and select Virtual Machine Storage. The pop up window allows the selection of VM files from the top pane and then dragging them to file locations in the bottom pane.
Once all changes have been made, click Start.
Windows install continues during Storage Migration
Failover Cluster Manager will display feedback on the progress of the storage move.
Modify number of simultaneous migrations
Similar to the improvements in Live Migration, Server 2012 also allows more than one migration at a time. Administrators can limit the number allowed.
This article focused on Storage Migration. The next and final article of the series will take a closer look at Replication.