reducing mailbox size doesn't free up disk space

[tylerdurden68]

Running Exchange 2003 with outlook 2003 clients on XP. Had a user with an enormous mailbox (around 5gb). Manually archived old mail to their My Docs folder, now their exchange mailbox is less than 1MB. This should have given me 5gb on the data disk on the Exchange server, or so I thought. The disk space remained unchanged. Is there something i need to do to reclaim the disk space for a mailbox that has been reduced in size?

 

[58sniper]

Couple of reasons why you don't see an increase of drive space. The first is the Deleted Item Retention settings on the Mailbox Store. This keeps deleted items in the dumpster for the specified period before permanently deleting them from the database.

Second - If you look in the event log, you should see a 1221 event that indicates how much whitespace is in the database. The database doesn't really shrink in file size when you have less data in it. It simple has whitespace in it. It'll reuse that whitespace as it needs it before making the database bigger. You could do an offline defrag of the database, but that takes time, shuts your users out of their email, and doesn't yield any performance gain. In fact, Exchange can use existing whitespace faster than it can expand the database.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP
Want to know how email works? Read for yourself -

http://www.ietf.org/rfc/rfc2821.txt

 

[Spirit]

One other thing that can affect this is single instance storage. For instance if they had 50 mails at with 100MB attachments even thugh you've deleted the attachments other users in the same store may also have those (received the same mail, been forwarded it etc.) so they will not be removed from the store.

Having said that 999 times out of 1000 Snipers' explaination is spot on.

Iain

 

[Zelandakh]

Exchange is designed not to reclaim the whitespace from disk so I'd say Pat is right 1000/1000.