Compacting the DHCP Server Database

Windows 2000 and Windows NT Server 4.0 are designed to automatically compact the DHCP server database. However, if you are using Windows NT Server version 3.51 or earlier, the database might need to be compacted after DHCP has been running for awhile to improve performance. You should compact the DHCP database whenever it approaches 30 MB.

You can use the Jetpack.exe utility provided with Windows NT Server 3.5 and 3.51 to compact a DHCP database. Jetpack.exe is a command-line utility that is run in the Windows NT Server command window. The utility is found in the %SystemRoot%\System32 directory.

The Jetpack.exe syntax is:

Jetpack.exe database_name temp_database_name

For example:

CD %SystemRoot%\SYSTEM32\DHCP

JETPACK DHCP.MDB TMP.MDB

In the preceding example, Tmp.mdb is a temporary database that is used by Jetpack.exe. Dhcp.mdb is the DHCP server database file.

When Jetpack.exe is started, it performs the following tasks:

1. Copies database information to a temporary database file called Tmp.mdb.
2. Deletes the original database file, Dhcp.mdb.
3. Renames the temporary database file to the original file name.

To compact the DHCP database

1. Open the DHCP Manager console.
2. Select the applicable DHCP server.
3. Click Action, point to All Tasks, and click Stop. (Alternatively, you can type net stop DHCP at the command prompt.)
4. At the command prompt, type jetpack to run the Jetpack program.
5. Restart the DHCP service by using the Services dialog box.

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