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Because the Global Catalog data is already present in the .DIT file for
the domain for which the server is a DC. Its in effect single instance storage -
its not going to duplicate the data that's already there.
--------------------------------------------------------------
Roger D. Seielstad -
MCSE
Sr. Systems Administrator
Inovis Inc.
OK, that makes sense and is consistent with
everything else. That actually goes back to another conversation a few weeks
ago when someone was asking about the true advantages/disadvantages of a
dedicated forest root vs. single domain. The single domain would have a
smaller GC (only one to manage).
One thing it doesn't answer is why the size of
the dit file doesn't change if a system is not a GC. In one case, a system was
temporarily made a GC and then "demoted" again to just a DC. However there are
other DCs that were never GCs at any time. Every one of them is approximately
250MB (within 2 MB in either direction depending on the DC).
Marc Zukerman
Senior Network Engineer
Greenwich Technology Partners
----- Original Message -----
Sent: Wednesday, March 26, 2003 10:17
AM
Subject: RE: [ActiveDir] AD
synchronization
Since you are one
domain the sizes should be the same. The GC contains the partial attribute
set from all domains in the forest. Since you only have one domain you don't
have anything additional added. Also, yes the GC is a subset of all
attributes for the domains which the DC is not a member. So again, since you
are a single domain nothing is added. Also the NTDS.dit contains all naming
contexts, Domain, Configuration, Schema... so within the dit for the DC there
will be domain naming contexts for all domains in the forest. Other than the
domain which the DC is representing the DC only have partial information for
all objects in the other domains.
Even though only
some of the users are on Exchange 2000, the definition of the user objects
come from the schema which define exchange attributes. There are no values
for the attributes but the user objects have those attributes present
(Speaking of mail enabled users).
In a multiple
domain forest the GCs will be larger because they have all of their own info
as well as some info from all other domains...
Hth,
Kevin
Sullivan
Sales
Engineer
Aelita
Software
-----Original
Message-----
From: Marc
Zukerman [mailto:[EMAIL PROTECTED]
Sent: Wednesday, March 26, 2003 9:58
AM
To:
[EMAIL PROTECTED]
Subject: Re: [ActiveDir] AD
synchronization
Now that's interesting Roger. I
never thought to check it, but at my current client, the ntds.dit file does
NOT change between GCs and DCs. For a directory of roughly 8500 objects we
are at 250MB for all domain controllers, whether or not they are a DC. This
environment is a single domain with Exchange 2000 (although only a very
small subset of the users have Exchange - that's the project we're
doing).
Also, I've always assumed that
the GC was smaller than the DC because it is merely a subset. A large one,
but a subset nonetheless.
Greenwich Technology
Partners
----- Original
Message -----
Sent:
Wednesday, March 26, 2003 7:30 AM
Subject: RE:
[ActiveDir] AD synchronization
That's a tough
one. Its going to depend on the number of domains and the number of
objects in each domain.
We're using an
empty root with a single 'production' domain below it, probably 2500
objects in the production domain.
Looking at two
root DCs, one which is and one which isn't a GC, the sizes of NTDS.DIT are
significantly different:
So,
roughly speaking, that's about 50MB for a GC replication of around 2500
objects. Of course, your mileage will vary quite a bit. So, in my
case, a full GC replication is going to be about 50MB to 12 servers, which
my WAN can handle without issue - most WAN's could probably handle
that.
--------------------------------------------------------------
Roger D.
Seielstad - MCSE
Sr.
Systems Administrator
Inovis
Inc.
-----Original
Message-----
From: Don
Murawski (Lenox) [mailto:[EMAIL PROTECTED]
Sent: Wednesday, March 26, 2003
7:02 AM
To:
'[EMAIL PROTECTED]'
Subject: RE: [ActiveDir] AD
synchronization
How "big" is
the GC synch compared to the full AD synch?
-----Original
Message-----
From:
Marc Zukerman [mailto:[EMAIL PROTECTED]
Sent: Tuesday, March 25, 2003
2:29 PM
To:
[EMAIL PROTECTED]
Subject: Re: [ActiveDir] AD
synchronization
Yes. Any
schema modification requires a full directory synchronization. Since
the schema is forest-wide, this means it affects all whether there is
a dedicated forest root or not. In addition, the first Exchange 2000
system forces a global catalog full synchronization. When I questioned
the Microsoft developer at MEC '99 why it was necessary to replicate
the GC completely, I didn't get a satisfactory answer as to why. If
anyone out there can tell me, I'd love to know why. We all determined
it would be best to handle the forestprep and initial server
installation off hours and from the Schema FSMO for any environment
that was sizeable.
Greenwich
Technology Partners
-----
Original Message -----
Sent:
Tuesday, March 25, 2003 2:09 PM
Subject:
RE: [ActiveDir] AD synchronization
Does Forest
prep cause a full synchronization?
We have an
empty root domain that contains the schema
master.
-----Original
Message-----
From: Marc Zukerman
[mailto:[EMAIL PROTECTED]
Sent: Tuesday, March 25, 2003
12:22 PM
To: [EMAIL PROTECTED]
Subject: Re: [ActiveDir] AD
synchronization
Even so,
I wouldn't chance it. If you have any corruptions to the schema
when it gets updated, it is much more difficult to deal with that
at 2:00pm on a Wednesday. I'd shoot for Friday night to be
safe.
Greenwich
Technology Partners
-----
Original Message -----
Sent: Tuesday, March 25,
2003 11:57 AM
Subject: RE: [ActiveDir] AD
synchronization
How big
is the AD implementation and how big are the pipes? I ran forest
prep here in the middle of that day with 30 DC's and 10,000 AD
objects not a problem at all. 768 CIR lines between
servers.
--
Kevinm WLKMMAS, Exchange MVP
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Marc
Zukerman
Sent:
Tuesday, March 25, 2003 8:42 AM
To:
[EMAIL PROTECTED]
If you
have not run forestprep yet, it will update the schema. This
will force a full synchronication of the directory and global
catalog. This may be a concern.
Greenwich Technology
Partners
-----
Original Message -----
Sent: Tuesday, March
25, 2003 10:42 AM
Subject: [ActiveDir] AD
synchronization
We
are bring up one E2k server this weekend, the
exchange group is concerned the AD synchronization will impact
Active Directory to a point that service is
crippled.
What are the major
impacts?
Don
L. Murawski
Sr.
Network Administrator
![]()
WorldTravel
BTI
Phone:
(404) 923-9468
Fax:
(404) 949-6710
Cell:
(678) 549-1264
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