Exchange backups a problem?

74 Gigs should *NOT* take 24 hours to back up.  Keep in mind, we are not going to tape, we are backing up to Disk Storage Units and then copying backup images from disk to tape later.  So tape bandwidth is not the issue here.

I’ve been working on an exchange backup problem.  Now I know that the exchange server in question was not set up as “best practices”.  Single information store, (used to be installed on the C: drive, we finally moved that) for about 350 users.  The new exchange server is coming online soon (not soon enough for my tastes) but for now this is what I have to work with.

A single stream backup has taken about 24 hours to complete, even for differentials, using the default directive:

Microsoft Exchange Mailboxes:\

You create a single stream for all mailboxes.

So knowing there has to be a better way to do this, I tried the usual wildcard, as follows:

Microsoft Exchange Mailboxes:\*

With disasterous results.  The system spawned 400+ backup streams, which held the entire backup environment hostage.  Half the backup jobs couldn’t run within the 5 hour window we had set for ourselves.  A little research through the Symantec/Veritas site (their site is not exactly easty to sift through) turns up the following set of directives in the “Exchange Administrator’s Guide”:

NEW_STREAM
Microsoft Exchange Public Folders:\
NEW_STREAM
Microsoft Information Store:\
NEW_STREAM
Microsoft Exchange Mailboxes:\[a-e]*
NEW_STREAM
Microsoft Exchange Mailboxes:\[f-j]*
NEW_STREAM
Microsoft Exchange Mailboxes:\[k-o]*
NEW_STREAM
Microsoft Exchange Mailboxes:\[p-t]*
NEW_STREAM
Microsoft Exchange Mailboxes:\[u-z]*

Now the first two are easy – back up the public folders, and back up the information store as a whole.  Backing up the information store as well as the mailboxes can be said to be a bit redundant, however this is a big deal if you have to do a full restore – restoring from the Information store backup is much much faster than the item by item backup.  It’s a waste of time until you’re down and need it, so is worth the extra time / storage. 
The remaining directives group a collection of mailboxes into a single stream.  In our case we’ve put all mailboxes starting with A through all mailboxes starting with E in the single stream.  F through J in the second stream, etc.

There is further tuning that can be done, moving sets of mailboxes from one stream to another to balance them out.

Only time will tell if this really helps.  My testing indicates that using 5 streams, show that the 500-600 Kps slows to 300-400kps, but when multiplied by 5 streams it still looks like this might be an improvement.

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