Re: [ActiveDir] x64 domain controller sizing?

Wed, 01 Feb 2006 12:55:45 -0800

More is always better :)
One clarification if it helps:
The 4:1 processor recommendation assumes that you have like processors.  Since it's a swag to begin with (although based on testing) it's usually OK.  The recommendation was supposed to read: "4 (MHZ) : 1 (MHZ)" and is there to reflect the cpu usage expected when introducing an Exchange server.  Since that recommendation, I'm sure there have been those that agree and those that disagree with that as an initial recommendation. DDG's also make a BIG difference in this sizing as does memory configuration on the Exchange servers and the GCs being used at the time.
 
 
"
•

All Exchange servers and users should have fast access to a global catalog server.

"
Hmm... I've seen some pretty fast WAN links lately.  Not sure I can tell the difference between a LAN, a CAN, a MAN, and a WAN connection these days. Latency, cost and available bandwidth are the only differentiators in many of the networks I've seen. 
 
The end of the day, just be sure that a GC is always available to your Exchange server.  Sizing is more of an art based on science. 
 
But don't take my word for it.  Ask around and do your own trials.  YMMMV.
 
On 2/1/06, Ion Gott <[EMAIL PROTECTED]> wrote:
This may be helpful to everyone as well:
 

Global Catalog Servers

Global catalog servers are required for logon because they contain information about universal group membership. This membership grants or denies user access to resources. If a global catalog server cannot be contacted, a user's universal membership cannot be determined and log on access is denied.

  Note

Although Windows Server 2003 provides features that do not require a local global catalog server, you still need a local global catalog server for Exchange and Outlook to use. The global catalog server is critical for Exchange services (including log on, group membership, store services) and access to the global address list (GAL). Deploying global catalog servers locally to both servers and users makes address lookups more efficient. Contacting a global catalog server across a slow connection increases network traffic and impairs the user experience.

Consider the following when placing global catalog servers:

•

All Exchange servers and users should have fast access to a global catalog server.

•

At least one global catalog server must be installed in each domain that contains Exchange servers.

•

There should generally be a 4:1 ratio of Exchange processors to global catalog server processors, assuming the processors are similar models and speeds. However, depending on your situation, higher global catalog server usage, a large Active Directory, or large distribution lists can necessitate more global catalog servers.

 
Ion V. Gott
 

From: [EMAIL PROTECTED] on behalf of Mauricio F. Funes
Sent: Wed 2/1/2006 10:25 AM
To: [email protected]
Subject: RE: [ActiveDir] x64 domain controller sizing?

 
Many factors have to be taken into consideration.
1- Are you planning to have a dedicated AD site for Exchange, in other words are this GCs going to be dedicated for Exchange?
2- Are you planning  to allocate sufficient memory to hold the the DIT in memory?
3- Distribution group expansion, does you company realy on using large distribution lists? (DG expansion affects GC performance)
4- Are you looking at implementing Dual Core servers?
 
These are the things that might affect the number of GCs you implement.....
 
 
 
Mauricio Funes
 

From: Al Mulnick
Sent: Wed 2/1/2006 10:06 AM
To: [email protected]
Subject: Re: [ActiveDir] x64 domain controller sizing?

 
Really?  I didn't get that from the documentatioin the same you mention.  I always took it that you wanted to put it on the same network to avoid network issues where possible, related to WAN connectivity or latency.  Basically, Exchange is so dependent on a GC that you want to provide the best possible situation for it to be able to communicate with as few opportunities as possible for something to go wrong.  Fewer moving parts as it were.
 
Best bet is to follow the other post from Joe which mentions coming up with your own benchmarks.  That takes a lot of the ambiguity out of the equation.
 
Be sure to put plenty of memory in the new machines.  ;)

 
On 2/1/06, Ion Gott <[EMAIL PROTECTED]> wrote:
I believe the number of GC's would really still be dependent on your site topology, number of objects published to the GC, number of child domains in the forest etc.. and location of Exchange servers in relation to users. Also if clients are using applications that are directly dependent on the GC, like online Outlook GAL lookups.
 
The Active Directory Sizer tool Microsoft released early during the Windows 2000 release really is pretty much useless as it references pretty old hardware such as 700Mhz Pentium II Xeon processors and there really isn't much else available on the MS site as far as specifics. They usually just say things like have a GC located close to clients that use GC dependent processes such as the GAL and having redundant GC's in sites that contain Exchange servers.
 
 
Ion V. Gott
 
 

From: [EMAIL PROTECTED] on behalf of Jeremy Olson
Sent: Tue 1/31/2006 4:22 PM
To: [email protected]
Subject: [ActiveDir] x64 domain controller sizing?

 
Is there any recommondations for the number of x64 GC to exchange 2003 servers?  We are about to start deploying 2003 domain controllers.  I would rather use fewer x64 servers.  The dit file is about 4.6 gigs.

Thanks

Jeremy

 

 

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