More or Less? 2

[Gazzieh]

I am posting this here due to the fact that the base system will be Server 2008.

I am redesigning a network and as such am exploring the current system against the desired result.

My colleague and I have found a point of disagreement and so I would very much appreciate everyone's thoughts...

We have currently 11-13 servers with individual roles. The Domain Controllers (2) only concern themselves with that role (DHCP, DNS, log in, etc), while we have a server for file shares, one server for Exchange, one as the Proxy Server, one for printers, etc.

The disagreement is as follows:

Should we consolidate into a small body of servers (3 or 4) that handle all rolls and thus reduce confusion of which server should respond to a call? However we open ourselves up to potential network failure if a simple service fails on a server and it takes the server out (so, the Print Service collapses and removes the DHCP, DNS and login elements as the server reboots).

Or should we keep with a diverse group of servers, thus spreading the load across many units but then create potential confusion between servers; with each one being polled to see which one should respond?

I suppose in line with this is: do we include ALL servers into managing AD functions and if not then how do we select the ones that do and the ones that stay outside?

 

[58sniper]

Without performance metrics, we can't say. But virtualization might help reduce the server sprawl, while still allowing you to keep things separated.

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[Gazzieh]

Baisc outline is that we are a split site secondary school with 1200 students and 120 staff. We have the standard school model of every hour we will have mass log on, mass log off and large groups of students accessing the same resources at the same moment.

Most of the servers are on one site, with a replication server at the lower one. The connection at present is a 1Gb fibre line but will be 10Gb minimum very shortly.

I suppose I would like someone to give the circumstances under which either methodology works; or is one simply wrong.

Hope this gives more information.

 

[58sniper]

Well, having multiple DCs and multiple GCs would be fairly important. You could virtualize most of the resources, but some you don't want to, including the DC holding the PDC emulator role and any Exchange mailbox servers.

Pat Richard MVP
Plan for performance, and capacity takes care of itself. Plan for capacity, and suffer poor performance.

http://www.ucblogs.net/blogs/exchange/

 

[kmcferrin]

My suggestion would be to have a DC and GC at each, with all the FSMO roles being held at the primary site. Keep the single Exchange server. I would virtualize pretty much everything else, and cluster the Hyper-V machines for failover.

You didn't mention what you were using for your proxy, but if it is in the perimeter network (or actually serve as a firewall as well) then I would not virtualize that either. If you would need to virtualize it then I would put a separate Hyper-V host in the perimeter network that the internal servers cannot fail over to.

Assuming that your hardware supports it, of course.

________________________________________
CompTIA A+, Network+, Server+, Security+
MCTS:Hyper-V
MCTS:System Center Virtual Machine Manager
MCSE:Security 2003
MCITP:Enterprise Administrator

 

[theravager]

Sounds like you are looking at a major upgrade.

Assuming you fibre link to the other site that you are upgrading to 10G is fine I would probibly buy a small blade chassis to put everything in. Blades these days are super reliable when compared to standalone servers.

I would also have a really really close look at virtualisation. You could probibly easily run everything on 2 maybe 3 nodes with failure. I would however leave one domain controller still as physical.

If you do virtualise i would stay away from hyper v until 2008 R2 is out down the track unless you get software for nix under education deals.

 

[kmcferrin]

Why stay away from Hyper-V until R2 comes out? Certainly R2 will have more features than the current version, but the current version is more than adequate for most smaller organizations. Especially when you pair it up with System Center Virtual Machine Manager (and Operations Manager, i fyou want to go that far). If you're going to have to purchase the Windows Server licenses anyway, you might as well use Hyper-V since you get that for free. The alternative is paying for someone elses hypervisor, which ends up being more expensive and complicates your upgrade path when R2 comes out later this year.

________________________________________
CompTIA A+, Network+, Server+, Security+
MCTS:Hyper-V
MCTS:System Center Virtual Machine Manager
MCSE:Security 2003
MCITP:Enterprise Administrator

 

[Gazzieh]

Wow! Thanks everyone. It's not often that I hit a gold mine of information but this has been a revolution!

My colleague and I have now to look into costs etc but the key element is with the Virtualisation. I am assuming from these posts that Hyper-V is Microsoft's own and is included with Server 2008. What version (or is it all of them?) and is there any additional licence implications?

 

[kmcferrin]

Hyper-V is included with Windows Server 2008, as long as you don't buy the version that specifically states "without Hyper-V". It comes with Standard, Enterprise, and Datacenter editions.

If you buy Standard Edition you get 1 virtual license in addition to the physical license. This means that you could install Server 2008 Standard w/Hyper-V and then install a single virtual instance of Windows Server 2008 on that physical server.

If you buy Enterprise Edition you get 4 virtual licenses in addition to the physical license. This means that you could install Server 2008 Enterprise w/Hyper-V and then install 4 virtual instances of Windows Server 2008 on that physical server.

If you buy Datacenter Edition you get unlimited virtual licenses. This means that you can install Server 2008 Datacenter w/Hyper and install an unlimited number of virtual isntances of Windows Server 2008 on that physical server (until you run out of memory, of course).

Keep in mind that the "virtual licenses" are still tied to a physical machine, so if you are likely to be moving VMs between servers you will have to license each server for the high watermark. For example, say you have two servers and need to deploy 8 VMs. You can buy two copies of Server 2008 Enterprise, and install it on each of your two servers. Then you can install 4 VMs on each of your two servers for a total of 8 VMs. But if you move one or more VMs from one physical host to the other then one of them will have more than 4 VMs on it, exceeding the limitations of the license. So if you are likely to move VMs (or configure a failover cluster) you will need either 2 Enterprise version licenses (for a max of 8 VMs) per physical server in this case, or Datacenter edition on each physical server.



________________________________________
CompTIA A+, Network+, Server+, Security+
MCTS:Hyper-V
MCTS:System Center Virtual Machine Manager
MCSE:Security 2003
MCITP:Enterprise Administrator

 

[SimonDavies]

I would also look into the implications of moving those machines, when I looked into it there was a time limit between moving machines, for instance if you moved a machine off a host for some reason you couldn't move it off the next host until a period of time (90 days but I could be wrong).

Simon

The real world is not about exam scores, it's about ability.

 

[kmcferrin]

Simon, I think that you're confusing the transfer of licenses with moving VMs. If you want to transfer a license from one server to another, you're only allowed to do that once every 90 days. When it comes to migrating VMs between Hyper-V (or VMWare, Xen, etc) hosts, you can do that as often as you like. However, each of your hosts has to be licensed for the "high water mark".

For example, if you have two Hyper-V hosts, each running Server 2008 Enterprise, you can run 4 VMs on each host. If you wanted to migrate one of those VMs to the other host (i.e., the split would go from 4 and 4 to 5 and 3), then you would have to have additional licenses assigned to that host with 5. You can't count the one "extra" VM license that you had on the other host, because that license is tied to that specific host.

________________________________________
CompTIA A+, Network+, Server+, Security+
MCTS:Hyper-V
MCTS:System Center Virtual Machine Manager
MCSE:Security 2003
MCITP:Enterprise Administrator