In-Depth

So You've Had an Operations Master Die...

All is not lost. Chart your options before you kill the Operations Master for good.

• By Jeremy Moskowitz
• 03/01/2001

If you're going to do some scheduled maintenance on a Domain Controller (DC), you may wish to transfer one of the Single Operations Masters from the box that's going to be down. You can do this via NTDSUTIL.exe or with the appropriate MMC snap-in tool. (For more information about seizing or transferring operations masters, be sure to check out Microsoft Q255690, "How to View and Transfer FSMO Roles in the Graphical User Interface," and Q255504, "Using Ntdsutil.exe to Seize or Transfer FSMO Roles to a Domain Controller.")

If a domain controller that houses a Single Operations Master goes belly up, you'll need to make some judgments about the situation. First, will you be able to get the machine back up and running?

If you think you will be able to bring the box back up, your next question should be how long until it's back in action? If the answer is less than a day or so, my advice is to just do everything in your power and focus on getting that machine back up.

If you'll be unable to get the box back up and running (because, for example, restoring from tape has failed), then you've pretty much got no choice other than to have another DC seize ownership. Seizing ownership of a role is, quite possibly, the most "violent" thing you can do to your Active Directory. Do so when necessary — but only when absolutely necessary.

Note that once you seize certain roles, that original box can never be reintroduced back into the domain. As a good friend likes to say: "Drown it, stir it, and drown again." That's FDISK to you and me, folks.

Here's a chart detailing the operations masters, what they do, and when you should finally bite the bullet, give up and seize a role.

Operations master	Description of role	Domain- or forest-wide role?	Affects users directly?	When you should give up and seize the role	Notes
PDC emulator	Does everything the NT 4.0 PDC did (and more)	Domain	Yes	When your non-Win2K users complain about the inability to log on	You can have another DC seize the PDC emulator role, then transfer back when the original box is back online (if desired)
Schema master	Makes sure schema changes happen in one place then get replicated	Forest	No	When you have to make schema modifications (an infrequent occurrence, one hopes)	Once role is seized, re-install Win2K Server on the original DC. Not doing so could corrupt AD
Domain naming master	Makes sure domains get added properly, and the information is replicated correctly	Forest	No	When you have to add a new domain (an infrequent occurrence, one hopes)	1: Always put this role on a DC that's also a Global Catalog server. 2: Once role is seized, re-install Win2K Server on the original DC. Not doing so could corrupt AD
RID master	Hands out RIDs (the later portion of a SID) to objects	Domain	No	You'll know you've run out of RIDs because you'll see error messages when creating new accounts. This may happen faster if you have NT 4.0 BDCs in your domain	Once role is seized, re-install Win2K server on the original DC. Not doing so could corrupt AD
Infrastructure Master	Tracks the movement of user objects between OUs and domains	Domain	No	If you get errors moving accounts within a domain, you'll know it's time.	1: Don't put this role on a DC that's also a Global Catalog server. 2: You can have another DC seize the Infrastructure Master role, then transfer back when the original box is back online (if desired)