Umar DBA: Utilizing Up to 3GB Virtual Memory on Windows NT Server 4.0

Subject:	Utilizing Up to 3GB Virtual Memory on Windows NT Server 4.0
	Doc ID:	Note:1036312.6	Type:	PROBLEM
	Last Revision Date:	02-MAY-2006	Status:	PUBLISHED

Problem Description

===================

On Windows NT Server, Enterprise Edition 4.0, Microsoft provides the 4GT (4GB

RAM Tuning) support so an application can utilize up to 3GB virtual memory

instead of the 2GB limit as it used to be.

The Windows NT service pack 3 provides the same feature but is not officially

claimed in the SP3 readme.txt.

The Oracle 8.0.3 release and higher have already been enabled to take

advantage of the new feature.  The Oracle 7.3.4 release and 7.3.3.4.0 patch

releases will also be enabled for the new feature.

Solution Description

====================

If you have Oracle 7.3.3, you need to run the following command:

imagecfg -l oracle73.exe

This also requries a switch in the boot.ini file. The switch, /3GB, is placed

at the end of the line that executes the WinNT loading process.

Example:

[operating systems] multi(0)disk(0)rdisk(0)partition(2)\WINNT="Windows NT

Server Version 4.00" /3GB

The above is all on one line within the boot.ini.

With Oracle 7.3.4, 8.0.3 and 8.0.4 there is no additional configuration

required to make use of this additional RAM.

NOTE: There may be a case where you are running 8.0.4.3.7 on NT and the 3gig

      address issue required the use of imagecfg to access the larger address

      space. One major reason might be the fact that patch sets may have

      brought in an executeable without the flag being set.

Solution Explanation

====================

The Windows NT Server, Enterprise Edition includes a feature called 4GB Memory

Tuning.  This feature allows applications to utilize up to 50% more RAM.  4GB

Tuning does this by reducing the potential RAM allocated to the Windows NT

kernel from 2 GB to 1 GB thus increasing potential RAM allocated to

applications from m2 GB to 3 GB.

To make use of this new capability on version 7.3.3 the imagecfg.exe, bundled

with Windows NT Server, Enterprise Edition 4.0,  must be run.  Since

imagecfg.exe is not automatically installed, you will need to copy it from the

CD manually.

NOTE: Oracle Fail Safe requires Windows NT Server, Enterprise Edition.

Windows 2000

==============

This information is valid for Windows 2000 systems also.  Please review

the information from Microsoft on which versions of Windows 2000 support

this switch:

http://support.microsoft.com/?kbid=291988

Umar DBA