Backup of Exchange giving wrong byte count

[David_Hoch]

I'm running Backup Exec 10d for Small Business Server on a Windows 2003 Small Business Server.  I'm backing up to an HP DAT72 USB Tape Drive.  Due to the quantity of data that needs to be backed up I have split my backups so that Exchange is being backed up on a tape seperately from the backup of any data files.

When I do a Test Run of the Exchange backup (which includes the Information Store, the Mailboxes, and the Public Folders) Backup Exec indicates that approximately 18GB of data will be included in the backup.

When I run the backup it backs up approximately 40 GB of data (which is the capacity of the tape).

Two Questions:

1) Why does the Test Run show a different Byte Count than the actual running of the job

2) Does the selection of the Information Store and the seperate selection of the Mailboxes cause the information to be backed up twice, taking twice the space on the tape?  

Thanks for your help with this.

--David

[Andrew_Styler]

Yes backing up the stores ie the .stm and .edb files  and the mailboxes double the backup sizes.

As you are using exchange 2003 you can make use of the recovery storage group to do invidiual mailbox restores using exmerge to save out the mailbox you want to restore.

http://hellomate.typepad.com/exchange/2003/12/the_recovery_st.html

You can them move items from this exmerged Pst into the mailbox proper.

Bricklevel backups are slow and problematic and not a MS recomended way.

I personally don't do brick level backups anymore, as the speed of doing this can be incredably slow due to the way each item has to be read and possibly virus scan before streaming to tape.