2003 Exchange & Enterprise OS Memory usage   

The Exchange cluster is getting physical and Virtual memory usage of over 90 
and 50% relatively.  The OS is 2003 R2 Enterprise with SP1, and exchange is 
Enterprise 6.5 Build 7638.2 SP2.  Memory is currently 4GB with the /3GB 
switch in the boot.ini.  

If memory was increased to 8GB or > and the /PAE switched used, does this 
benefit Exchange, the OS, or both?

Any insight would be helpful.  Thank you

date: Tue, 8 Jan 2008 09:19:00 -0800   author:   Marc J

Re: 2003 Exchange & Enterprise OS Memory usage   

Exchange 2003 is not PAE aware and cannot use memory over 4GB.  In fact, if 
you add more than 4GB of memory and/or enable PAE, you can cause serious 
instability.


"Marc J"  wrote in message 
news:09DD7685-F337-477B-8C89-CA78EB272124@microsoft.com...
> The Exchange cluster is getting physical and Virtual memory usage of over 
> 90
> and 50% relatively.  The OS is 2003 R2 Enterprise with SP1, and exchange 
> is
> Enterprise 6.5 Build 7638.2 SP2.  Memory is currently 4GB with the /3GB
> switch in the boot.ini.
>
> If memory was increased to 8GB or > and the /PAE switched used, does this
> benefit Exchange, the OS, or both?
>
> Any insight would be helpful.  Thank you

date: Tue, 8 Jan 2008 10:46:32 -0800   author:   John Fullbright fjohn@donotspamnetappdotcom

Re: 2003 Exchange & Enterprise OS Memory usage   

This link seems to tell a different story about running exchange with /pae.   
I agree exchange probably won't see the additional memory, but will it help 
the OS.

Can I have anyone's thoughts on this article, and my comment above?  thank 
you.

http://msexchangeteam.com/archive/2005/07/05/407330.aspx



"John Fullbright" wrote:

> Exchange 2003 is not PAE aware and cannot use memory over 4GB.  In fact, if 
> you add more than 4GB of memory and/or enable PAE, you can cause serious 
> instability.
> 
> 
> "Marc J"  wrote in message 
> news:09DD7685-F337-477B-8C89-CA78EB272124@microsoft.com...
> > The Exchange cluster is getting physical and Virtual memory usage of over 
> > 90
> > and 50% relatively.  The OS is 2003 R2 Enterprise with SP1, and exchange 
> > is
> > Enterprise 6.5 Build 7638.2 SP2.  Memory is currently 4GB with the /3GB
> > switch in the boot.ini.
> >
> > If memory was increased to 8GB or > and the /PAE switched used, does this
> > benefit Exchange, the OS, or both?
> >
> > Any insight would be helpful.  Thank you 
> 
> 
>

date: Tue, 8 Jan 2008 11:13:04 -0800   author:   Marc J

Re: 2003 Exchange & Enterprise OS Memory usage   

"Marc J"  wrote in message 
news:64B67572-B652-4E8D-BE68-483E302473A2@microsoft.com...
> This link seems to tell a different story about running exchange with 
> /pae.
> I agree exchange probably won't see the additional memory, but will it 
> help
> the OS.
>
> Can I have anyone's thoughts on this article, and my comment above?  thank
> you.
>
> http://msexchangeteam.com/archive/2005/07/05/407330.aspx

As John said, it has been known to be a problem. Don't bother.

-- 
Russ Kaufmann
MVP - Windows Server - Clustering
ClusterHelp.com, a Microsoft Certified Gold Partner
Web http://www.clusterhelp.com
Blog http://msmvps.com/clusterhelp

The next ClusterHelp classes are:
Mar 10- 13 in Denver
May 12-15 in New York

date: Tue, 8 Jan 2008 13:48:04 -0700   author:   Russ Kaufmann [MVP]

Re: 2003 Exchange & Enterprise OS Memory usage   

> As John said, it has been known to be a problem. Don't bother.

Thirded.

Oliver

date: Tue, 8 Jan 2008 22:06:41 -0000   author:   Oliver Moazzezi [MVP]

Re: 2003 Exchange & Enterprise OS Memory usage   

There are many conflicting articles on the subject

http://msexchangeteam.com/archive/2005/12/14/416065.aspx

This one is newer.

The reality is that enabling PAE effectively halves thenumber of available 
PTEs.  This can lead to situations on a heavily loaded server where you run 
out.  You don't want that to happen. c That's what meant by "signifacant 
drawbacks in terms of kernal memory management".  Even though you could 
remove the /3gb switch to give more memory to kernal mode, MS "does not 
recommend removing the /3GB switch if your server meets the criteria for 
which this switch is recommended".  That pretty much leaves you with 
disabling PAE.

If you run out of PTEs., all your storage calls will fail with C000009A. 
This means lost delayed writes and data corruption.  You don't want to run 
out.




"Marc J"  wrote in message 
news:64B67572-B652-4E8D-BE68-483E302473A2@microsoft.com...
> This link seems to tell a different story about running exchange with 
> /pae.
> I agree exchange probably won't see the additional memory, but will it 
> help
> the OS.
>
> Can I have anyone's thoughts on this article, and my comment above?  thank
> you.
>
> http://msexchangeteam.com/archive/2005/07/05/407330.aspx
>
>
>
> "John Fullbright" wrote:
>
>> Exchange 2003 is not PAE aware and cannot use memory over 4GB.  In fact, 
>> if
>> you add more than 4GB of memory and/or enable PAE, you can cause serious
>> instability.
>>
>>
>> "Marc J"  wrote in message
>> news:09DD7685-F337-477B-8C89-CA78EB272124@microsoft.com...
>> > The Exchange cluster is getting physical and Virtual memory usage of 
>> > over
>> > 90
>> > and 50% relatively.  The OS is 2003 R2 Enterprise with SP1, and 
>> > exchange
>> > is
>> > Enterprise 6.5 Build 7638.2 SP2.  Memory is currently 4GB with the /3GB
>> > switch in the boot.ini.
>> >
>> > If memory was increased to 8GB or > and the /PAE switched used, does 
>> > this
>> > benefit Exchange, the OS, or both?
>> >
>> > Any insight would be helpful.  Thank you
>>
>>
>>

date: Tue, 8 Jan 2008 18:27:41 -0800   author:   John Fullbright fjohn@donotspamnetappdotcom