I have a file "vaultlogcf.mdf" that has grown to 5GB.  It was 3GB yesterday and the system has only archived 300MB overnight ... any way to shrink this?

You can do a shrink through SQL Management studio

OPen SQL management Studio
Select your database
Right Click on the database
Navigate to Tasks
Navigate to Shrink
Navigate to database

DO NOT CLICK on the Reorganize tick boox as it will take a long time for this to run

Click OK and this will shrink the databse

Next repeat the process but this time select files
Then click on Release unused space

You have to repeat again for files but second time select LOG as file type instead of Data

Ideally you should set this up as a weekly maintainance job to defrag, reindex and compress each database

thanks, but that only shrunk the 'vaultlogcf.mdf' file by 100MB out of 5GB when I did the shrink database. Once I did shrink files/logs (sql 2005) -- the mdf file went back up to 5.1GB.  I've repeated the shrink database and the same result of only 100MB smaller out of 5GB.

Is this 'vaultlogcf.mdf' storing all the historical data of when i was testing the archiving for this mailbox (I archived 5GB then exported it out to PST/mailbox and deleted what was in the vault/archive)?  

My enterprise vault currently only has 300-500MB of archived mail in it ... I don't feel the vaultlog.cff should be anywhere near this size ...

It does seem excessively large because my archive is 40TB and my database and log are 9 and 7GB respectively