Re: exch 2003 /3GB problem
- From: "John Fullbright [MVP]" <fjohn@donotspamnetappdotcom>
- Date: Tue, 23 May 2006 09:29:43 -0700
Optin, the default, enables the PAE Kernal. This is specifically why you
use optout; to prevent the PAE kernal from loading.
http://support.microsoft.com/kb/875352/en-us
For Exchange, you do not want to load the PAE kernal. When the PAE kernal
is enabled, each PTE takes twice as much memory, effectively cutting the
number of available PTEs in half.
http://support.microsoft.com/kb/311901/en-us
When you use userva=3030, you are giving an additional 42mb of RAM to
kernal mode for PTEs. If the number of PTEs are low, you may want to
decrease this number a bit.
http://support.microsoft.com/kb/823440/en-us
MSExchangeIS - Largest VM Block Size
http://support.microsoft.com/kb/325044/en-us
The only way the HP claim could be true would be if the application
supported PAE: Exchange does not support PAE. The /PAE switch does make the
OS report 4GB instead of 3.5 on PCI Express systems, but the .5GB is
unusable by Exchange. Looks like smoke and mirrors to me, not a performance
enhancement.
..3.5GB of RAM.
<REPRINT>
Well it's a long and sad story that starts with the features of the hardware
you are using. On the Dell 2850, the bios chipset implements PCI Express.
This reserves a 256MB memory region for PCI extended configuration, and
256MB for the PCI memory region of each card installed. That's a grand
total of 768MB if you have two cards (standard config for Dell 2850). This
means that only 3.25 GB of your 4GB is able to map below the 4GB mark. The
remaining .75GB maps above it. If this were not Exchange, you could enable
the PAE kernal to see the additional memory. Do not do this on an Exchange
server. Your only other option is to go to the vendor for a bios update.
It's real tempting to say "Uh, it's a Dell" and leave it at that, but the
problem affects all vendors using the Intel E7520 chipset or the AMD Opteron
8000 chipset on their motherboards. It impacts HP, IBM, and probably many
others as well.
<REPRINT>
"Adoyt" <Adoyt@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:552730CF-74CD-4101-89E5-F7C829F314A8@xxxxxxxxxxxxxxxx
John,
I've read that the /noexecute=optout switch enables PAE. What do you
think
about HP's claims that this will hurt performance?
http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=PSD_EL041214_CW01
I currently have servers that are showing 3.5 GB of RAM.
"John Fullbright [MVP]" wrote:
1. If you're at windows 2003 SP1, also include /NoExecute=optout in the
boot.ini
2. The fact that you're on a SAN does not automatically mean that the
storage is sized properly. Check your physical disk sec/write counters
to
make sure your response times average under 20ms with no spikes over 50ms
lasting more than a few seconds.
3. You may need to use a value loke 2970 instead of 3030 for userva.
4. One of the most important VM counters is largest VM block size, what
is
the value of this?
"Carpadum" <Carpadum@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:37D716CC-85CA-44C8-A231-FA0BD633024F@xxxxxxxxxxxxxxxx
We have Windows Server 2003 Enterprise edt. w/ 2 proc and 4 Gig of
memory.
Exchange is also Enterprise Edt. and it is configured w/ 4 Storage
Groups
and
each storage group has a min. of 2 Mailbox stores. The total database
size
of all these groups is around 65Gig. I have entered the following in
the
boot.ini
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(2)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Windows Server 2003,
Enterprise" /fastdetect /3GB /Userva=3030
(note the last entry is all on one line in the boot file)
I have also done the recommended reg edits to
HeapDeCommitFreeBlockThreshold
setting
When I do a perfmon on the Store.exe / virtual Bytes, the value is
around
100 on the graph w/ .0000010 as a scale. When I look at the Free
System
Page
Table Entries, the value is 2200 w/ .0100 scale. This seems way off to
me!
I am concerned that something is not running correctly. Why would the
store
process never use more than 1,100,000K of memory?(there is almost 2 gig
free
on te server) Why would there be so much free memory on a database of
this
size? The data lives on a SAN so it is a very fast machine, I just
feel
that
memory issues are holding it up.
.
- References:
- Re: exch 2003 /3GB problem
- From: John Fullbright [MVP]
- Re: exch 2003 /3GB problem
- From: Adoyt
- Re: exch 2003 /3GB problem
- Prev by Date: Re: SMTP error during SP2 install
- Next by Date: Re: Second Exchange server off-site?
- Previous by thread: Re: exch 2003 /3GB problem
- Next by thread: Exchange 5.5 - Exchange 2003
- Index(es):
Relevant Pages
|
