Proper Backup of Open Files Using Ntbackup

• Microsoft Windows NT Workstation versions 3.51 and 4.0
• Microsoft Windows NT Server versions 3.51 and 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\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

Perform one of the following to resolve this problem:

• WARNING: Using Registry Editor incorrectly can cause serious, system-wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of Registry Editor can be solved. Use this tool at your own risk.

  Set the following value to 0:

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

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