Proper Backup of Open Files Using Ntbackup

• Microsoft Windows NT Workstation versions 3.51, 4.0
• Microsoft Windows NT Server versions 3.51, 4.0

SYMPTOMS

Files may not be properly restored with a backup program (such as Windows NT Backup).

CAUSE

This problem can be caused by either of the following:

• Corrupt file
  
  Some third-party backup programs set the following value to 1 during setup while Windows NT Backup sets this value to 0:

  HKEY_CURRENT_USER\SOFTWARE\Microsoft\Ntbackup\Backup Engine\Backup files inuse

  Open files are generally in an inconsistent state and any attempt to back up these files may cause corruption (for example, WINS and DHCP databases).



• Missing file
  
  If the value above is set to 0, the backup program skips open files; therefore, some files may be missing when you restore from backup.

RESOLUTION

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

For information about how to edit the registry, view the "Changing Keys and Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it. If you are running Windows NT, you should also update your Emergency Repair Disk (ERD).

Perform one of the following to resolve this problem:

• Set the following value to 0:




HKEY_CURRENT_USER\SOFTWARE\Microsoft\Ntbackup\Backup Engine\Backup files inuse

• Make sure a consistent file is available for backup before you start the backup. To do this, perform one of the following:



• Application method
  Use a utility for that application file that creates a good backup while that file is open. For example, rdisk -s backs up the registry in the %SystemRoot%\Repair folder.
  
  NOTE: When performing a remote backup of any server's registry, you must run rdisk -s or rdisk /s- on that server first because remote registries are not available to be backed up over the network.



• System method
  Close the files before backup (for example, stop logons, close current sessions with existing clients, and stop all non-essential services). You may be able to accomplish this by using the AT command or the Command Scheduler (Winat.exe).



• Application and System method
  The best approach may be to use both methods to make sure all data is accessible from a backup and to test your plan fully before implementing it.

MORE INFORMATION

If the following value is 1, backup programs attempt to back up open files:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\Ntbackup\Backup Engine\Backup files inuse

Additional query words:

Keywords : nt32ap ntbackup NTSrvWkst ntutil
Version : winnt:3.51,4.0
Platform : winnt
Issue type : kbhowto