I ran into some trouble with a Hyper-V 3.0 Windows Server 2012 environment , randomly VM’s would enter paused state when Data Protection Manager 2012 performed a backup , Event ID 16060 VM has been paused because it ran out of disk space on C:\Clusterstorage , but after looking at both the CSV and the VM itself there was plenty of space.
Moving the CSV owner to a dedicated node without VM seemed to solve the problem but as soon as Dynamic Optimization kicked in the host had VM pause again when the backup ran.
After looking around I found this thread http://social.technet.microsoft.com/Forums/en-US/winserverClustering/thread/7a7ddaca-fb09-4c9a-b0ae-9f3b5e10694d , showing other having the same problem.
So thank you to all thread posters especially Vladimir from Microsoft and Trevor from Outsourcery and Joe from Catapult systems pointing to KB2791729 for resolving the issue
So either move the CSV owner to a node without VM’s or contact Microsoft for a private hotfix until its available for everyone or look in the thread above.