This article explains how to balance I/O between VM’s on hosts that are saturated. It’s a last resort action to resolve the issue. Ideally you’ll be balancing your workload across a cluster, e.g. OpsMgr detects a peak load, your storage PRO tips detect the culprit and VMM 2008 balances the workload across the Hyper-V cluster. However, that won’t work if you don’t have a cluster so using these registry edits might be necessary.