Modifying SBS 2003 SP1’s bkprunner.exe for Improved Backup Performance

http://blog.chrisara.com.au/2007/09/modifying-sbs-2003-sp1s-bkprunnerexe.html

 

I’ll quickly jot this down before I forget.
I’ve recently been having a shrinking backup window on one of my client’s SBS 2003 boxes. It backs up to tape and I didn’t want to create a backup script and lose the nice reporting features that SBS provides. So I hacked the bkprunner.exe process instead :-)
On my own SBS 2003 box I was getting terrible server performance during my daily backup to USB drives. I found the undocumented /FU switch that was included with the SP1 version of ntbackup and some registry modifications that the Exchange team of Microsoft IT performed to improve their backup performance.
Open Explorer and go to "C:\Program Files\Microsoft Windows Small Business Server\Backup"
Make a copy of bkprunner.exe

Download and extract XVI32.
Run XVI32.exe
Open bkprunner.exe in XVI32
The address range $10F0-$11B7 is used for backups to .bkf files
The address range $11B8-$1277 is used for backups to tape
To turn off verify when backing up to a .bkf
Go to address $113A
In the hex pane (the middle one), type in the following hex values:
6E 00 6F 00 20
This enters in the text "no " in Unicode format.

To turn off buffered writes (as explained in MSKB 839272 and also here) when backing up to a .bkf – recommended
Go to address $115E
In the hex pane (the middle one), type in the following hex values:
46 00 55 00 20 00 20 00 20 00 20
This enters in the text "FU " in Unicode format.

To turn off verify when backing up to tape
Go to address $1202
In the hex pane (the middle one), type in the following hex values:
6E 00 6F 00 20
This enters in the text "no " in Unicode format.

Registry modifications for performance
Run regedit
Open HKEY_USERS
Load Hive
Open SBS Backup User’s NTUSER.DAT registry hive; call the key name BACKUP
Browse to HKEY_USERS\BACKUP\Software\Microsoft\Ntbackup\Backup Engine.
Edit the value of the entry Logical Disk Buffer Size from 32 to 64.
Edit the value of the entry Max Buffer Size from 512 to 1024.
Edit the value of the entry Max Num Tape Buffers from 9 to 16.
If the above keys don’t exist, create them as String values.
Click on HKEY_USERS\BACKUP
Unload hive

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