If I have Exchange 2003 SP2 mailbox servers, with for example 200gb IS file size (.edb and .stm file size combined, just as an example) and I have 50gb of whitespace....how much data will be backed up? The full 200gb, or only the 150gb active data? A collegue mentioned he thought whitespace was excluded but we haven't been able to find confirmation. If its excluded, is this done by the Exchange API's and is irrelevant of backup product? Or the backup products Exchange agent? If it has any bearing on the discussion, we have Backup Exec and Netbackup and varying locations, and both use their relative Exchange agent.

Backup software will back the database as is so it will back up 200GB. Because to most backup software that is just another file to backed up.

Thanks Michael, thats sort of what I thought originally also. But if your using backup software that has an Exchange agent, specifically designed for live Exchange backups (even potentially NT Backup), does this1) "look into" the database and extract the real data? Which should give you a backup size that is minus whitespace. 2) Or does it just quiesce/quiet the DB and do something like VSS snap the DB file in its entirety which is then written to tape?

On Wed, 10 Mar 2010 23:21:11 +0000, Ricky.E wrote:>Thanks Michael, thats sort of what I thought originally also. But if your using backup software that has an Exchange agent, specifically designed for live Exchange backups (even potentially NT Backup), does this1) "look into" the database and extract the real data? Which should give you a backup size that is minus whitespace. 2) Or does it just quiesce/quiet the DB and do something like VSS snap the DB file in its entirety which is then written to tape? Backups (streaming ones, at least) are done at the database pagelevel. There's no inspection of the data within the page (with theexception of the forward and backward links and the page checksum).---Rich MatheisenMCSE+I, Exchange MVP--- Rich Matheisen MCSE+I, Exchange MVP