I'm running Exchange 2003 Enterprise SP2 on Windows Server 2003 SP2. While doing some routine maintenance tonight I decided to look at the mailbox sizes as reported in my ESM. After doing some quick math in my head I felt like something was up with the total. It appeared to be far greater than what I had recently seen reported via the physical files. I double checked and the physical size of my private information store's .edb and .stm files totaled together is 190 GB. When I sum up all the mailboxes as reported in my ESM the total size equals 265 GB. I am not experiencing any problems related to my private or public store sizes, but I am baffled by this data. Some Google searches have yielded no help to this peculiar problem. This scenario does not seem possible given my understanding of how exchange database sizes work. Any ideas? Jimmy Holmes

Hi Jim, Nice observation. But anyways I think its because of single instance storage. Also storage engine (ESE) might cause the difference. Thanks, Vinit Vinit Nair MCSE | MCTS - Exchange 2007 "Sanity and happiness are an impossible combination."

Hi Jim, Nice observation. But anyways I think its because of single instance storage. Also storage engine (ESE) might cause the difference. Thanks, Vinit Vinit Nair MCSE | MCTS - Exchange 2007 "Sanity and happiness are an impossible combination."

Hi Jim, When Exchange mailboxes are calculated SIS is not taken into consideration. whilst this kb isn't explicitly for your question, it goes some ways to explain SIS in Exchange 2003 http://support.microsoft.com/kb/175481 OliverOliver Moazzezi | Exchange MVP, MCSA:M, MCITP:Exchange 2010, BA (Hons) Anim | http://www.exchange2010.com | http://www.cobweb.com | http://twitter.com/OliverMoazzezi

Hi Jim, When Exchange mailboxes are calculated SIS is not taken into consideration. whilst this kb isn't explicitly for your question, it goes some ways to explain SIS in Exchange 2003 http://support.microsoft.com/kb/175481 OliverOliver Moazzezi | Exchange MVP, MCSA:M, MCITP:Exchange 2010, BA (Hons) Anim | http://www.exchange2010.com | http://www.cobweb.com | http://twitter.com/OliverMoazzezi

Oliver & Vinit - Thanks guys! While I'm not that familiar with SIS I had read about it earlier in the evening and I suppose that makes sense. It's just that the 75GB seemed like such a large spread that something seemed out of order. Are there any tools that can help me identify those pointers so that I can verify the difference?<o:p></o:p> Jimmy<o:p></o:p>

eseutil may help if you take a space dump. This may help. Sukh