(Posted by Mike Cessna, Anexinet Solutions Architect):
I just wanted to send this link out since I’ve had to explain this to a few clients in the last few weeks due to old or outdated recommendations they received from other consulting companies.
The old rule (windows 2000) was to never have the Global Catalog reside on the Infrastructure Master role holder. However it’s not as simple as that old ‘rule of thumb’ made it seem and was quickly dropped by MS. The problem is that many engineers kept the rule alive due to ignorance of the actual processes involved.
The short explanation is that the GC can reside on the Infrastructure master when only a single domain forest is in use or if all the DC’s in the forest are GC’s. Typically all DCs in a forest should be a GC due to a variety of factors, but normal deployment is for all DCs to be GCs, therefore we could care less where the Infrastructure role is placed.
It’s strange how many times I’ve had this conversation with clients. This is an old rule that hasn’t been true in over 10 years. The clients usually ask why the other consultant did it this way and I have to explain that this is the way it was done long ago but is no longer true and
Here’s a link to a MS doc explaining FSMO role placements.