Keep in mind that one of the features of Live Migration is that the original virtual machine and/or files are not removed until after the entire process is complete. This “bur no bridges” approach ensures that your virtual machine remains running no matter what happens during the migration process. I’ve seen this personally during the preview releases of WS2012 and WS202 R2 when stress testing Live Migration and other features.
Microsoft has published a KB article for when Hyper-V storage migration fails when you try to migrate VHD and configuration files to CSV volumes in Windows Server 2012.
Consider the following scenario:
- You install the Hyper-V role on a Windows Server 2012-based two-node failover cluster.
- You have two Cluster Shared Volumes (CSV) volumes.
- You create a virtual machine on a cluster node. The virtual machine has a single 60-gigabyte (GB) fixed-size virtual hard disk (VHD).
Note The virtual machine is not created on a CSV volume.
- On the cluster node, the available space on drive C is less than 20 GB.
- In the Hyper-V Manager console, you try to move the VHD file to one CSV volume, and you try to move the configuration files to the other CSV volume.
Note The CSV volumes have enough space to hold the VHD file and the configuration files.
In this scenario, the migration operation fails, and you receive an error message that resembles the following:
Migration did not succeed. Not enough disk space at ‘\’.
Note This issue still occurs after you install hotfix 2844296. For more information about hotfix 2844296, click the following article number to view the article in the Microsoft Knowledge Base:
Shared Nothing Live Migration fails when you try to migrate a virtual machine to a destination server in Windows Server 2012.
This issue occurs because the target CSV volumes are incorrectly identified as being a system drive volume instead of multiple separate CSV volumes.
A hotfix is available to resolve this issue.