When the DHCP service first starts after an upgrade, 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.) The user is asked for confirmation before the conversion process starts. If the user clicks OK, the DHCP service stops and the conversion begins. Jetconv.exe converts the databases of all the installed services (DHCP and, if installed, WINS and RPL) to the new database format.
After the DHCP database is converted successfully, the DHCP Server service automatically restarts.
Before starting the conversion process, note the following guidelines:
Before upgrading, bring the Windows NT 3.51 databases for the DHCP server to a consistent state. Do this by stopping the services by using the Services icon in Control Panel or by using the net stop service command.
The conversion requires approximately the same amount of free disk space as the size of the original database and log files. You should have at least 5 megabytes (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, watch the Application Event Log of the Jetconv.exe process by using Event Viewer.
In cases in which this automatic procedure of converting databases fails, the database can be converted manually by using winnt\system32\upg351db.exe.
Likewise, if this is the first time you start DHCP after an upgrade from Windows NT 3.51, you need to run the conversiontool (upg351db.exe in the winnt\system32 folder) on the DHCP database to convert it to the new, improved database format. After the database has been converted, restart DHCP.
To perform these procedures, you must be a member of the Administrators group, or you must have been delegated the appropriate authority.
To upgrade the database:
Run upg351db.exe from the winnt\system32 folder.
After the upgrade, click Start, type services.msc in Start Search, and then press ENTER.
Click Continue, right-click DHCP Server, click Restart, and then click Yes to restart the DHCP Server service.