I have a 30GB database that seems to be growing moderately every month. I have about 55% free disk space and was wondering if it would be wise to consider defragging the database and shrinking the size. I know you have to have twice the size of the database + 10% to do a successful defrag or integrity check. I can't add anymore physical disk as the drive bays are full. My concern is this: In 9 months we will be moving to Exchange 2007. I am concerned that during thenext nine months I may face the unlikely event that I have to to an integrity check on the database and I will not have enough space to do this if the database continues to grow. I am trying to be proactive even though the chance is unlikely I will need to do this. Any opinions? Thanks, Alex

Your mail store will only shrink by the amount of white space. You can get a sense of this amount by adding up all the mailbox sizes. If the total mailbox sizes equal less then your database file size then you have white space. If the mailboxes equal more then your mail store file size then you have Single Instance Storage saving space and you won't recover any physical disk space from a defrag. All and all a 30GB mail store is really not that big. I would skip the defrag unless you have a bunch of white space. In the off chance you have to do an integrity check to move to 2007 you can always plug in a USB drive for some extra space (or port the tmp file to a network location but this is fairly slow). Are you planning on bringing up a second server for 2007 or an in-place upgrade?

The above comment by stodj is partially correct, however adding up mailboxes may not really give you the whitespace, as single instance store can have a big impact. Look for event 1221 in the application log. this will tell you how much space you might get back. (there will be seperate event log entries for the public and private information stores.) http://support.microsoft.com/kb/555323 Unless the number is really worth it, Microsoft does not recommend you defrag just for fun. Also, stodj asks about an in-place upgrade, which is also incorrect. You cannot upgrade 2003 to 2007. You must use a new server and migrate mailboxes. I hope this is what you had in your plan, otherwise, you'll need to make that change. I do agree with the overall point - don't worry about it, and use a network location or usb drive if you get into a pinch.

also, if you need to get your database down to size, you can adjust mailbox and deleted item retention time down to 0. this can help a great deal. (just be sure to fix it when you get disk space back)