I’ve seen a number of customers run into networking and general communication issues following a move to Windows 2008 R2. And to manage Windows 2008 R2 you must be running SCVMM 2008 R2. Both require checking for updates.
Windows 2008 R2 – Make sure the network card drivers are up to date… all of them. If the server vendor does not have drivers updated for Windows 2008 (or R2), check the site of the actual NIC manufacturer as most built-in NICs are simply rebranded. This will solve a majority of your networking issues off the bat. Make sure you update the drivers on the VMM Server as well as the Hosts.
SCVMM 2008 R2 – Did you upgrade from SCVMM 2008 to SCVMM 2008 R2? If so, you should check each Host in the SCVMM Admin Console to determine if the agents have been updated. If not, update them now by right clicking on them and selecting ‘Update Agent.’
If you have performed the actions detailed above and are still experiencing communication issues with Hosts you can uninstall the ‘Microsoft System Center Virtual Machine Manager Agent’ manually on the Hosts from ‘Control Panel> Programs and Features.’ After this, go back to the SCVMM Admin Console, remove the Host by right clicking on it and selecting ‘Remove Host.’ Once removed, add it back with the Admin Console by selecting ‘Add Host’ under Actions on the right side of the console. This will clear up any agent update issues.
This covers two of the most common issues seen lately. If still experiencing issues check some of the other posts on this site that address other possible reasons. Good luck, and enjoy the new product!
Free Evaluation Download!System Center Virtual Machine Manager 2008 R2 – Evaluation http://www.microsoft.com/downloads/details.aspx?FamilyID=292de23c-845c-4d08-8d65-b4b8cbc8397b&displaylang=en