Performance tips for EX2003 on a DC

[tmckeown]

I have Exchange 2003 Enterprise on a Win 2003 server that is also a domain controller and global catalog server. We did this due to the fact that we were having troubles (years ago) with the other DC being too busy to handle request made to the Exchange server. So, I figured that by making the Exchange server a DC, that would help. LDAP request went straight to the Exchange Server. It did solve some problems years ago, but now I would like to tweak the performance if possible. I have run the Exchange Best practices Analyzer Tool and followed all the steps it said to take.

During th course of a day, some of the users get a "Outlook is requesting data from.." message and Outlook sort of hangs for a while. (10-20 sec.) That's the main problem.

I've checked all the logs and there are no errors. I've run DCDIAG and found no problems. The server is a dual 3GHZ Xeon with 4 GB ram. System idle process usually sits around 99%, so I find it hard to believe I'm taxing the system in any way, other than the hard drives. We pass a lot of huge files each day. The average is 10MB. Many of the mailboxes are near 1GB though I do have them limited to 90 days worth of stuff in their inbox. The nature of our business requires us to send and receive large files, so that can't change. What could the lack of responsiveness be?

Can someone fill me in on:
Why is it best not to have exchange on a DC? (I can't change this)
How can I improve performance?

Thanks for the help,
Tom

 

[Xanaxo]

I would bet it is your database(s). How many transaction logs do you have being generated each day? Do you run full backups? I am guessing you have a large database. I find that most databases that are large, when not dismounted before a restart, will slow the shutdown process down. 10-15 min shutdown is common.

Here is what I recommend. Make sure you are at the latest services packs, and perform an OFFLINE defrag of your databases. This is a must for any heavily used databases and should be practiced on a regular basis. (At least once every few months on a large database). By doing this you will recover whitespace, and make sure your database is in tip-top shape. It will also give you a chance to be proactive and identify any problems that could leave you in disaster one day if not addressed.

Remember to plan an outtage period as this is a very long offline event that will take several hours on a large database.


Here is some information on performing an offline defrag:

http://support.microsoft.com/default.aspx?scid=kb;en-us;192185#XSLTH3131121122120121120120

http://support.microsoft.com/default.aspx?scid=kb;en-us;328804

Steven Parent [MSFT]

 

[tmckeown]

Xanaxo,
Thanks for the reply. The database is quite large. Actually, the mailboxes were just recently moved to this server from an older mail server. So, I'm not sure that the defrag could fix it, unless the data can get fragmented while moving. I keep checking the logs, but I don't see anything that could cause a slowdown. The logs are free of errors and warnings. The problem is somewhat intermittent, so maybe it is just network traffic?

 

[Xanaxo]

You are probably right about that. Just rememeber to offline defrag from time to time to keep the database in optimal condition.


I would also say that if the problem is intermittent, then it might be as designed. Read what I posted about that issue recently.

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There can be a single cause or several related causes for this particular dialog box. The "Requesting data from Exchange server..." dialog appears when Outlook 2002 or 2003 has not received a server response to a request for 5 seconds or more. So anything that could cause a response to be delayed may be suspect. Some configuration options in Outlook can cause more requests to be generated so the chances of a 5 second delay rise just because of the frequency of requests. Networking issues may affect the time the response takes to be returned and performance issues on the server can cause slower responses.

The fact that these "Requesting dialog from server..." dialogs appear is not always a sign of a persistent issue. If they appear once a month for a second or two that could possibly be normal. If they appear everyday for seconds to minutes at a time then there is something causing latency in the client receiving a response to an outstanding server request.

The article below is a good place to start.

839862 How to troubleshoot the RPC Cancel Request dialog box in Outlook 2003 or

http://support.microsoft.com/?id=839862

Steven Parent [MSFT]


Steven Parent [MSFT]