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Q158473: Upgrading the DHCP Database to Windows NT Server 4.0

Article: Q158473
Product(s): Microsoft Windows NT
Version(s): WinNT:3.51,4.0
Operating System(s): 
Keyword(s): kbnetwork
Last Modified: 09-AUG-2001

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The information in this article applies to:

- Microsoft Windows NT Server versions 3.51, 4.0 
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SUMMARY
=======

When upgrading a Windows NT Server version 3.51 (or earlier) release to Windows
NT 4.0, the DHCP database must be converted to the new database format. This
conversion is required because the services now use an improved database engine
that is faster and compacts automatically to prevent fragmentation and
consequent growth of the database. The database conversion procedure happens
automatically as part of an upgrade installation.

MORE INFORMATION
================

When the DHCP service first starts after an upgrade to Windows NT 4.0, it
detects that the database needs to be converted. It then starts a conversion
process, Jetconv.exe. (If Jetconv.exe has already been started by another
service, a second Jetconv.exe process is not started.) Prior to conversion, the
user is notified that the conversion process is about to start and is asked for
confirmation. If the user clicks OK, the DHCP service quits and the conversion
begins. Jetconv.exe converts the databases of all the installed services (DHCP
and, if installed, WINS and RPL) to the new Windows NT 4.0 database format.

After the DHCP database is converted successfully, the DHCP server service
automatically restarts.

Before starting the conversion process, note the following guidelines:

- Prior to upgrading to Windows NT Server 4.0, bring the Windows NT 3.51
  databases for the DHCP server to a consistent state. Do this by stopping the
  services from Control Panel\Services or by using the net stop service
  command.

- The conversion requires approximately the same amount of free diskspace as
  the size of the original database and log files. You should have at least 5
  MB free for the log files for each database.

- The conversion process preserves the original database and log files in a
  subdirectory named 351db under the same directory where the original database
  and log files were located. On the DHCP server, this is the
  %SystemRoot%\System32\Dhcp\351db\ directory.

The services must not be restarted while the databases are being converted. To
check the status of the conversion, the user should watch the Application Event
Log of the Jetconv.exe process by using Event Viewer.

In cases where this automatic procedure of converting databases fails, the
database can be converted manually using winntdir\system32\upg351db.exe. For
instructions, type the following at the command prompt:

upg351db -?

Note the following information:

- You cannot convert the new database back to the previous database format.

- The converted database will not work with Windows NT 3.51 or earlier
  services.

- The new database engine uses log files named by using the prefix J50.

Additional query words: upgrade

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Keywords          : kbnetwork 
Technology        : kbWinNTsearch kbWinNT351search kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS351 kbWinNTS351search
Version           : WinNT:3.51,4.0
Issue type        : kbinfo

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