A. You can verify your Exchange single-instance storage ratio by viewing the Single-Instance-Ratio counter for the MSExchangeIS-Private and MSExchangeIS-Public objects. A ratio of 1 means you aren't seeing any benefits by using single-instance storage, and every message is already only stored once. A ratio of 2 means that on average, every message stored using single-instance storage exists in two mailboxes, so the technology is saving you some space.
In this interactive online training event SharePoint MVP Randy Williams shows you how your users can benefit from Microsoft's latest reporting technologies and how you can better manage the challenges of BI and SharePoint.