Domain Controller - 64-Bit and 32-Bit

[mapman04]

Can a 64-Bit DC (serving as the PDC emulator) co-exist with 32-Bit backup/redundant DCs? Does it matter hold old the server is? I want to implement a 64-Bit DC and was asked if an existing 32-Bit DC (a PIII 1.0 GHz box 512 MB Ram) running at the remote site across the WAN can still be used. Upgrading the DC is the first step for implementing an Exchange 2007 server. It probably can but would rather update it to a new 64-Bit machine as well. Any general thoughts or comments?

Thanks,

Mapman04

 

[Cstorms]

A 64bit DC with your primary concern of the PDC emulator role is a bit (ton) of overkill. There typically would be no reason to require a machine that would require the presence/usage of large (copious) amounts of RAM if its only a domain controller. A P3 1GHZ with 512 of RAM if only doing authentication is rated up to a 1000 users while staying under the desired perfomance counter thresholds set forth by MS (80% Proc, and whatever the RAM thresholds are).

Like I said if the only role of this machine is to process AD authentication you would be hard pressed to find logical reasons to upgrade to a machine that would be capable of running a 64 bit version of W2k3 server.

Saying that after I just took shipment on a dual core 3.0ghz with 3GB of RAM for a 750+ user environment is a bit hard, I know.. Hypocrite.. (big budget ;p)

Save your dough for a dedicated 64bit box for just Exchange keep your DC far away from that machine

Cory

 

[LWComputingMVP]

I have to agree - I used to run a 2000 AD for 1000 users on a couple of dual 300 MHz PII systems with less than 384 MB of RAM and there was NEVER a performance issue with AD. Sure, 2003 may add some more overhead - but it IS a 4 year old OS and it doesn't add THAT much.

 

[mapman04]

So should the DCs be 64-Bit machines/OSs? Doesn't it make sense to put the 64-Bit foundation in place, especially since Exchange 2007 requires 64-Bit? I am trying to put in the proper foundation/network backbone, knowing this is my chance to do so. Another significant upgrade might not take place for 3 to 5 years. Hence, the old 1 GHz box currently in use. Wouldn't setting the core networking functions at the same level provide a better foundation as Exchange and a SQL-Based ERP package are soon to be installed?

Mapman04

 

[LWComputingMVP]

Exchange and SQL should NOT be installed on a DC. So if this is a new machine you ultimately want to install Exchange on, then DEFINITELY, don't make it a DC. AD doesn't require 64 bit and you can always add it later. If you're going to start building a 64 bit infrastructor, starting with the DC is not what I would recommend.

 

[mapman04]

The DC is its own separate box. Would use VMWare and virtualize a redundant DC at corporate on a separate box. Would put a DC at the remote site. I was thinking 64-bit for all of those. The Exchange and SQL boxes would also be separate. So my train of thought was to put in the 64-Bit AD, then Exchange and finally the SQL App.

Mapman04

 

[58sniper]

Keep in mind that some things don't run on 64 bit machines, like the GPMC and the resource kit.

Also, if you use your DCs as print servers (like many companies do), research whether print drivers are available for the 64 bit version for ALL printers.

Using 64 bit machines also requires different versions of AV software and backup software.

I've got one environment that uses 64bit DCs, and has DHCP and DNS running, as well as Virtual Server. Other than the limitations I've mentioned, everything runs fine.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP

 

[mapman04]

So is the general recommendation to NOT run DCs on the 64-bit platform? I'm apprehensive to run the DC on such an old piece of hardware. I'd have a better (albeit maybe false) sense of security running on new hardware...or even a used piece of equipment that's not 5 to 6 years old. I don't want to spend money foolishly...but want to provide a solid, stable platform to build upon. To me, using a really old piece of hardware doesn't make a whole lot of sense.

Mapman04

 

[58sniper]

The hardware you're looking at for 64bit would run the 32bit OS just fine.

YMMV - just keep the limitations in mind as you decide. I don't think there is a right or wrong answer here. But 64bit might be more of a hassle than what it's worth. But that's for you to decide. I don't regret using 64bit DCs.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP

 

[kmcferrin]

Something else that I think I'm reading in your comments is that you think you'll eventually be on a totally 64-bit infrastructure. While that may eventually be the case as 32-bit Windows dies out, there's no requirement to move to 64-bit for machines that don't need the added resources. Active Directory is the same whether it is running on a 32-bit or 64-bit OS.

 

[mapman04]

Thanks for everyones input. One final question: If the budget allows, would everyone buy a new low-end box to use as a DC or would you take your chances on the old hardware?

Thanks again,

Mapman04

 

[Cstorms]

I think your last question is totally dependent on scalability and your current environment. You should gauge your need based on stats you gather right now. What I would do is look at some of the excellent Microsoft technet articles on AD architecture and see what they recommend in regards to baseline performance. From here you can determine what in your environment is really necessary, its always pleasant to find that you indeed can get away with spending less then you thought, this will give you some browny points if you overstated on your budget

Cory

 

[58sniper]

[google]take your chances[/google]

I don't like taking chances. But look at the docs and your environment as Cstorms said. What's your hardware lifecycle? I recommend three years - and that usually equates to 5 years when the bean counters get to it. I really like having hardware that's under the OEM warranty.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP