Windows 2008 or Windows 2003?
So you're about to deploy Exchange Server 2007 with Service Pack 1 and want to know which operating system to deploy. There are a number of issues that you should be aware of when you are making this decision so I thought I would summarise a few points...
The first has got to be the in-place upgrade path from Exchange on Windows 2003 to Exchange on Windows 2008. ....there isn't one. Have a look at these articles for clarification...
Exchange Server and Windows Server 2008
Mission Impossible: In-Place Upgrading Microsoft Exchange Server 2007 from Windows Server 2003 to Windows Server 2008
So in my opinion this is not a major hurdle - there will be loads of information available to administrators on how to migrate and it is likely to be a fairly simple, if time consuming, process. It's just that this needs to be planned for appropriately. If the decision is made not to go with Windows 2003; fine - but make sure everyone is aware of the investment that is going to be required somewhere down the line to move to Windows 2008.
Secondly Windows 2008 will run happily against a Windows 2003 Active Directory infrastructure. You need to understand the performance implications of your new Exchange Servers on your Active Directory infrastructure but your Exchange Servers could be your first Windows 2008 servers to be deployed. (Conversely if you are deploying Windows 2008 Active Directory you could run your Exchange 2007 SP1 Servers on W2K3 against your updated AD.)
Another obvious reason of course is the familiarity and maturity of Windows 2003. Most Exchange administrators are very familiar with Windows 2003 and there will need to be some level of investment in understanding Windows 2008 and being able to configure and administer the product successfully. However from my brief introductions to Windows 2008 the interfaces have been standardised and are very intuitive. If you are familiar with Windows 2003 configuring and administering 2008 is not such an enormous leap.
I have sat in numerous discussions where companies are designing for data centre resilience and need to understand the pros and cons of stretching CCR MNS cluster nodes between their data centres. Of course we know that SCR provides the recommended solution but for reasons I will not go into here many would prefer to use CCR. With Windows 2003 the sticking point was that each node of the cluster needed to be on the same subnet meaning that the network team needed to do some clever VLAN configuration to be able to offer this as a solution. In Windows 2008 the nodes can be in different subnet's and so this is now a genuine option for more companies faced with this situation. The following article describes configuring CCR on a Windows 2008 cluster: Installing Cluster Continuous Replication on Windows Server 2008
Of course the other reason is the new features and improvements that Windows 2008 brings. I don't want to go into too much detail here but here are some that will directly benefit the server when considering an Exchange deployment:
- Windows Deployment Services - will mean that you can deploy Windows more quickly and intuitively on the first and subsequent occasions. (WDS is the updated and redesigned version of RIS.) (See 'Step-by-Step Guide for Windows Deployment Services in Windows Server 2008')
- Cluster Management - the improvements in configuration and administration are dramatic in Windows 2008 particularly with failover clustering. A cluster is now very simple to setup and the cluster validation tool helps to ensure that the cluster is configured correctly.
- Performance - of course we can also expect performance improvements some of which should directly affect Exchange including improvements to memory management (there's a good whitepaper on this 'Advances in Memory Management for Windows') and SMB v2 (W2K8 uses an updated version of its default file sharing protocol) amongst others....
- Self-Healing NTFS - W2K8 will now attempt to correct corruptions of its NTFS file system online without requiring you to run 'check disk'. The NTFS kernel code has been enhanced so that this can be done without negative impacts to the system. (See Self-Healing NTFS)
It's also worth having a look at the 'Windows Server 2008 Security Guide' which it looks like has just been released.
So that was a very quick blog and probably only scratched the surface but thought it might be a useful place to kick off discussions.....