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My backupexec is setup to integrate with exchange, to backup the information store, versus just backing up the data file path.

My exchange mdbdata folder is 17 gigs. But my backup exec is backing up 40 gigs worth of data. I have gone through it a million times, and it's strictly backing up exchange information store.

I deleted all my backups and started over, to clear the incremental backup old data.

Where is all this extra data coming from?

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Doesn't Backup Exec have a job log that will tell you what file(s) and data it has backed up? – Bart Silverstrim May 24 '10 at 14:33
yea it says its backing up exactly what I said it did. But the size is more then double. – bladefist May 24 '10 at 14:50
up vote 2 down vote accepted

What type of backup are you running?

Various backup tools support different types of backup. One is the so-called brick level backup which backs the server at the mailbox level. A brick-level backup is far easier to restore in older versions of Exchange, but it comes at the cost of taking far more storage space.

This is because the exchange database does a lot of de-duplication aka single instance storage. A message sent to multiple users will be stored once and each user will have a pointer to it. When a brick-level backup is performed this de-duplication is undone, and each mailbox is backed up separately.

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Yes, the exchange integration in Backeup exce has you selecting all the mail boxes vs backing up the mdbdata folder. I think you are correct. I will investigate this further thanks – bladefist May 24 '10 at 17:23
Would it be better to just back up the mdbdata folder? Is that easy to restore...I would think you just restore the files and re-mount? I'm running exchange 2003. – bladefist May 24 '10 at 17:24
@bladefist - do not backup the mdbdata folder, you will not get a valid backup. You either need a database backup and possibly brick-level. – Doug Luxem May 24 '10 at 18:53

If you are backing up mailboxes as individual mailboxes you will see your backup set grow in size depending on the amount of duplicate data in each mailbox. Exchange 2003 uses SIS (single instance storage).

A recovery storage group can be used to restore individual mailboxes or mailbox items when you have only backed up the information store. Whether or not you use a recovery storage group or third part "brick level" backup depends on the following:

  1. SLA Time to recover the data - brick level backups are usually quicker to restore

  2. backup set size and time availability - backups using brick level backup can take dramatically longer (due to MAPI access limitations) in addition to the additional storage space required.

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So just backing up the mdbdata folder would be good enough? Restore time may take longer, but it will restore just as well? – bladefist May 24 '10 at 18:26
You must perform an actual exchange backup – Jim B May 25 '10 at 15:29

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