Is there any reason why exchange can't be run on a PDC? 2

[SimonDavis]

I have a bit of a conundrum, which basically means I need to run Exchange on the PDC - explanation is below if anyone is interested, but off the top of your heads, is there a yes/no for this one?

OK - reason for this (stop reading here if you're bored) . . .

I have 2 servers, and am installing Exchange 2007 - there isn't a forum here for that, hence this post.

2007 Must be run on a 64bit version of Windows. Fine, so I set up Exchange on 2.3kx64.

My other server must run 32 bit Windows, as x64 has very limited driver availability, and I can't run the network cards I have on x64.

I need to run the network cards because I need an ISA server . . .

So, the options here are limited. I can't run exchange on the same box as the ISA server (and wouldn't want to) as it has to be a 32 bit OS. I clearly don't want the ISA server to be the PDC. The only combination left is the have the 64 bit box as PDC, and it's the only one that will run exchange.

I'm in the planning stage right now, so all things are possible. The other option if REALLY necessary is to add another server, but that would only happen if I really can't run Exchange on the PDC. They're horribly expensive where I am.

What say you Tek-tips? Thank you in advance, as always.

 

[zbnet]

Exchange 2007 Forum:

http://www.tek-tips.com/threadminder.cfm?pid=1582

 

[mydogbites]

Its obviously not best practice but I run exchange 2003 here on our PDC, and its no problem as long as your machines got a good amount of memory.

 

[58sniper]

There are a bunch of reasons why you don't run Exchange on a DC.

Exchange should really be on its own box.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP

 

[SimonDavis]

Pat - thank you for the answer. If this is the only other role the server has, does that still create any serious issues?

This is a relatively small setup, I understand if we were on a big corporate network things would be different, but a certain amount of 'winging it' is necessary with a small setup, and even smaller budget.

I know this sounds like a 'please say yes' post . . heh.

Thanks ZBnet, I was coming in via the general page, I thought it odd that there apparently wasn't one.

Thanks mydogbites as well.

 

[CharlieIT]

If nothing else, you could put Exchange on a Virtual Server that runs on the DC. This would at least keep the environments separated. MS Exchange on a VS will work fine if this is a small network and you have enough resources on the DC.

 

[SimonDavis]

Thanks Charlie, that's an interesting idea.

I am throwing things onto a test network at the moment, and have installed 2007 on the PDC to see what happens - using the built in evaluation tool, it does (as Pat said) list a long number of reasons why putting it on the PDC is not good practice.

I have gone through most of them, and the most serious risk seems to be the most obvious - if the PDC falls over, so does the exchange box. Most of the other reasons don't really apply to such a small network.

I'm going to leave it as it is for the moment, and see how it performs. I've beefed up the servers anyway, they all have 4gb of RAM on D935 chips.

I realise I'm asking for advice and then refusing to accept any of it, but that's no disrespect to you people - our network isn't life or death, so I'm allowing a looser balance between budget and reliability than people with mission critical systems might.

Thanks again to everyone.

 

[ShackDaddy]

Here's the basic practical rule of thumb as I see it, clearing away most of the fog and: if you want to put Exchange on a DC, make sure it's a DC before you install Exchange. Never promote an Exchange server to be a DC.

And once you've installed Exchange, don't plan on demoting it. The real rule is this: never run DCPROMO on a server that has Exchange installed.

As far as load, that's not really the main reason why you wouldn't want them to share: it's not hard to put together powerful hardware, compared to when Exchange 2003 and Windows 2003 were first released. That shouldn't be big on the worry list unless you are planning on handling an enterprise Exchange environment (1000+ seats) on a single server.

The main other reason you wouldn't want to is because Microsoft PSS may balk at supporting you if there's a disaster recovery situation and it becomes too muddied by the AD/Exchange interplay... But I don't think it really gets all that muddy most of the time.

ShackDaddy
Shackelford Consulting

 

[58sniper]

If the GC role on the DC fails, Exchange will never use another GC.

In order for someone to administer Exchange on a DC, they have to have admin rights to the server. Since DCs don't have local admins, they have to be domain admins. Not the best solution if your Exchange admin isn't the domain admin.

Exchange will use all of your RAM up to 4 GB, so plan on your DC having more than that.

Don't plan on putting any Exchange related files on arrays that house any other data.

Disaster recovery is very difficult.

Updates that would require a reboot of an Exchange server now require you to reboot the DC.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP

 

[RichardHuang]

Running Exchange on DC is not recommended, but I have seen it on many small business. So don't too worry about it. I used to recover exchange servers on DC, from scrach. Completely reload OS and promte to DC, install exchange and restore database....They were okay. Technology is used to serve business, not the other way around. If you have small group of users, say, less than 60 users, I don't think it's a big deal to put them together.

 

[ShackDaddy]

I'll throw this in: Exchange recovery on a DC is much more complicated if there are multiple DC's in the domain. If you can afford multiple servers for DC's, you may be able to afford keeping Exchange off of a DC.

ShackDaddy
Shackelford Consulting

 

[58sniper]

A the only time that I'm aware of that Microsoft recommends putting Exchange on a DC is in SBS, and that's heavily engineered to be that way.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP

 

[ShackDaddy]

Simon, back back to your original post:

1) Let's question some assumptions. Why do you need to run ISA? Run ISA only if it's convenient, but ISA shouldn't be more important than Exchange 2007. Put in a SonicWall or FireBox if you need to. Much cheaper than a server and an OS. I personally stay away from ISA because I see it as unneeded complexity (due to it not being as "clean" and dedicated as an appliance) and a waste of a server.

2) I would keep your PDC on your 32-bit box and put Exchange on the 64-bit with no DC role there.

ShackDaddy
Shackelford Consulting

 

[58sniper]

Also, some things don't run on 64bit DCs, such as GPMC, the resource kit, etc.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP

 

[ShackDaddy]

Oh, and lastly, Microsoft DOES support Exchange 2007 on a DC. They didn't support E2003 on a DC. But I'd still avoid it in your environment.

I think some of us might have missed that we were dealing with Exchange 2007 at first, since you didn't mention it in your "thesis" sentence. I know I missed it.

ShackDaddy
Shackelford Consulting

 

[58sniper]

Actually, they DO support 2003 on a DC. They just don't recommend it.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP

 

[ShackDaddy]

Ah... They just don't support running DCPROMO on a server that has Exchange 2003 installed on it.

ShackDaddy
Shackelford Consulting

 

[58sniper]

Yeah, that's a bad thing to do. Very bad. Exchange go bye-bye.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP

 

[markdmac]

This thread should really be moved to the 2007 forum. Simon can you please post there and everyone else please consider this thread closed?

I hope you find this post helpful.

Regards,

Mark

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[SimonDavis]

OK - thank you all for your comments - I have read through these and also thought through a few more implications of what I'm trying to do here, and have concluded that for the time being I'm going to go with exchange 2003, which also obviates the need to go with x64 Windows.

There have also been some mountains to climb with antivirus and backup solutions for win x64.

Perhaps given my limited budget and skills, this was inevitable.

On the other hand, just to prove I'm still an idiot, I'm still going for separates, I just hate the idea of a cut down bundled solution like SBS. Can't say why, but I can't bring myself to do it . . .

Thanks to all of you, I'm sure we'll be talking again.