How to: Modify the size of your Windows Server 2008 R2 based DHCP server's JET database page cache at runtime

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You may want to consider modifying the JET database page cache size of your Windows Server 2008 R2 based DHCP server to take advantage of these possible benefits:

· Increasing the cache size improves active queue length, ACK/sec, and disk reads per second.

· All requesting clients should get addresses relatively quicker as a result of significant improvements in DHCP transactions. The server should respond to all V4 & V6 requests without keeping them long in the active queue.

You can change the size of your JET database page cache at runtime by modifying the JET_paramCacheSizeMax and JET_parmCacheSizeMin parameters of the Extensible Storage Engine (ESE). Typically, the cache automatically tunes its size as a function of database and server activity levels. If the JET_paramCacheSizeMax parameter is set to a value less than 2 MB, JET_paramCacheSizeMax will default to 2 MB as the upper bounds of the cache size. If it is set to a value greater than 2 MB the cache will adjust up to that size in database pages. JET_paramCacheSizeMax will not remain static at any upper bound value higher than 2 MB. Follow this procedure to configure the JET_paramCacheSizeMax parameter on your DHCP Server:

 

Configure the JET_paramCacheSizeMax parameter

1. Create or modify the registry key (DWORD) JetDatabaseMaxCacheSize at HKLM\SYSTEM\CurrentControlSet\Services\DhcpServer\Parameters\ . The default value is 2 MB. If the value is less than 2 MB, JETDatabaseMaxCacheSize will default to 2 MB.

2. Restart the DHCP Server service.

Corey Plett
Technical Writer
The Windows Server Networking Documentation Team