Exchange 2003 SP2 backup EXTREMELY slow, using clean BUE12 server/agents?

[hamdodger]

I have recently done a completely clean reinstall of BUE 12 as well as a clean reinstall of the updated BUE Agent and OFO agent on our Exchange 2003 SP2 server.  Previously on BUE 11d I would be able to back up out entire Exchange Information Store (45 GB) in a little over an hour.   Now with BUE 12 the process takes 4.5 hours.  Both Exchange Server and BUE server have 1 GB nics connected to the same backbone.   However I am only getting 90MB/min throughput on the backup.   Previously I know I was getting almost at least double this speed.  One difference is that I was attempting the granular (GRT) method of backup, but would this really cause such a massive slowdown in throughput?

Any idea why the sudden slow down?   Nothing else has changed.  The tape device connected to the BUE server is exactly the same, as is the media within it.

[Anup]

GRT backups are slower than Non GRT backups.

Legacy mailbox (brick level) backups are even slower than GRT backups 

[hamdodger]

My throughput still seems to be incredibly slow.  Both the server being backed up and the backup server have 1GB nics connected to the same switched backplane, and yet I'm only seeing about 94MB/s backup speeds.  Even when I did an initial full backup of the BUE server itself, it took nearly 2 1/2 hours to back up and verify 7 GB. I seriously don't recall getting this kind of performance out of BUE 11d.

I am using an Exabyte EXA-3 160/320GB tape archive connected via SCSI320 to the backup server.

[Anup]

Do you have consistency check enabled for exchange backups.?

Is service pack 2 installed for windows server?

Try copying large amount of data from backup server to another server and see how much time it takes 

[hamdodger]

No consistency check is running.  I have compression set to "Hardware if available) otherwise none" and I know this particular tape drive does do compression.   And yet I'm still only getting 97MB/min. throughput.

Other Exchange specific settings are:

Continuously back up transaction logs with Backup Exec Continuous Protection Server: No
Enable the restore of individual mail messages and folders from Information Store backups: No
Enable single instance backup for message attachments: No
Perform consistency check before backup when using Microsoft Volume Shadow Copy Service (VSS) snapshot provider: No
 

[Anup]

defrag the exchange database...

Also how much jobrate do u get if you backup normal file data instead of exchange from same server.

[hamdodger · Accepted solution]

Problem solved.

BUE 12 had overwritten the original device driver for the tape drive.  Once I replaced it with the vendor driver, the through put for backups went from 90 MB/min to nearly 700 MB/min.