Consider the following scenario:
In this scenario, an attempt to perform a shared nothing live migration of a virtual machine from one host to another will show a zero rating for the desired host and will display the following text in the Rating Explanation field:
Migration check for virtual machine <serverName> failed to create a planned virtual machine in the target host. Detailed error message: The Virtual Machine Management Service failed to establish a connection for a Virtual Machine migration with host serverName.contoso.com: No connection could be made because the target machine actively refused it. (Ox8007274D).
The connection error occurs when the VMM service tries to stage a virtual machine on the target host. If the host is configured to use a specific subnet for live migration, and if the VMM service does not use that subnet during the virtual machine staging, the host refuses the WSMan invoke command. VMM interprets the failure to mean that the host will not accept an incoming migration.
The placement helper in VMM does this intentionally to increase the likelihood of success during live migration. If VMM cannot validate that a given host will accept an incoming live migration, it does let the user select the host in the wizard.
To resolve this issue, make sure that VMM has the Host Migration settings configured to Use any available network.
To configure this setting, follow these steps:
This issue was resolved in System Center 2012 R2 Virtual Machine Manager.
For more information about how to perform a live migration on non-cluster virtual machines (also known as a "shared nothing live migration"), see the following resources:
Virtual Machine Live Migration Overview: http://technet.microsoft.com/en-us/library/hh831435.aspx
Configure and Use Live Migration on Non-clustered Virtual Machines: http://technet.microsoft.com/en-us/library/jj134199.aspx