What is the Max number of DC's in Win2k AD?

  • Thread starter Thread starter Jay
  • Start date Start date
J

Jay

Hey all,

I was recently told that there is a limit to the amount of
Domain Controllers you can have running in Win2k Active
Directory at one time. As in, things start to go haywire
after you reach a certain amount?

Is this true?

This guy wants to move to Win2003 and is using this
argument as his main ammo.

Can someone shed some light on this and maybe a Technet or
Microsoft article supporting it?

Thanks to all

Jay
 
He is probably referring to some limitations in Active Directory Branch
Office Delpoyments
(http://www.microsoft.com/windows2000/techinfo/planning/activedirectory/bran
choffice/default.asp) that existed in Windows 2000 and that have been
remedied in Windows Server 2003. The problem that exists has to do with the
way the KCC/ISTG in Windows 2000 Server worked - or rather didn't (very
well). It scaled only to hundereds of DCs in some environments.

This weakness has been all but eliminated in Windows Server 2003. That and
a number of other excellent product features are good enough reasons to move
immediately to Windows Server 2003. That's what we did in our 100,000-plus
user environment and we couldn't be much happier.


-ds
 
So you are saying that you had 100,000 plus users with
Windows 2000 and it was ok, but moved to 2003 for better
performance?

We currently have 90 DC's in our Forest and like I said,
one person is saying if we hit 100, life will end as we
know it.

Is this true?

I looked at the article you gave me and it just talks
about more administration with more than 100 DC's. Or at
least that is as far as I read.

Other examples within the same text talk about using
thousands of sites and not having a problem. Saying the
only limitation to the amount of objects is the amount of
disk space/memory.

In the end, our company may have as many as 2-300 domain
controllers in 4 domains, with as many as 30,000 users
worldwide. Is there a problem with staying a Win2k shop,
or is there ample (not just it would be nice) to move to
Win2003?

Thanks in advance.

Jay
 
<inline response>

Jay said:
So you are saying that you had 100,000 plus users with
Windows 2000 and it was ok, but moved to 2003 for better
performance?
Click to expand...

No. In this particular case, we did an in-place upgrade of 17 Windows NT
4.0 domains directly to a Windows Server 2003 forest. We carefully
evaluated Windows 2000 and determined our best course of action was to
bypass Windows 2000.

I had previously done a number of designs/deployments of Windows 2000 in
fairly large environments; one of them being a 20,000 user, 900 site design
for a large financial organization, that required significant tweaking to
make work properly. Windows Server 2003 would have worked in that
environment pretty much as-is.

We currently have 90 DC's in our Forest and like I said,
one person is saying if we hit 100, life will end as we
know it.
Click to expand...

No. Life clearly would not end as you know it with only 100 servers. If
you read through the Branch Office Deployment papers you will see that the
determining factors are as follows:

- Size of DIT
- Number of domains in the forest
- Number of Sites
- Number of DCs
- Hardware DCs are running on

Generally, a Windows 2000-based Active Directory begins to experience some
performance issues when the number of sites with DCs in them gets close to
about 300 - 500. After about 500 sites (sometimes more), the KCC may be
unable to complete its processing within the 15 min. interval - meaning the
forest configuration begins to fall behind.

Is this true?

I looked at the article you gave me and it just talks
about more administration with more than 100 DC's. Or at
least that is as far as I read.
Click to expand...

It *is* more administration - but eventually (as mentioned) you run into
performance issues with larger and more distributed systems. Yours doesn't
seem to fall inside this category. (but keep in mind, I havn't seen nor
evaluated your environment myself ...)

Other examples within the same text talk about using
thousands of sites and not having a problem. Saying the
only limitation to the amount of objects is the amount of
disk space/memory.
Click to expand...

With Windows Server 2003, you will not run into the same problems until you
reach beyond 3000 or more sites.

In the end, our company may have as many as 2-300 domain
controllers in 4 domains, with as many as 30,000 users
worldwide. Is there a problem with staying a Win2k shop,
or is there ample (not just it would be nice) to move to
Win2003?
Click to expand...

There should not be a problem (technically) with remaining a Windows 2000
shop. There are a ton of good reasons to migrate to Windows Server 2003
(reading through the features should convince you of that) and I'd begin
planning right away for that. But your environment shouldn't be having
problems with a Windows 2000 Active Directory.

Having said that - if I were you, I'd begin installing Windows Server 2003
instead of Windows 2000. Even within a Windows 2000 mixed/native forest,
the benefits will be tremendous.

We love our 2003 servers ... ;-)


-ds
 
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