*** Improved by Wrobinson on 02/29/08 ***
This is good informatin MrDenny, as usual but it jumps the gun a bit. First of all, there are several versions of Microsoft Exchange Server and Exchange Server 2003 is not the current technology, Exchange Server 2007 or E12 is. There are very different approaches to clustering in Exchange Server 2003/2000 and E12. The first order of business is to determine if clustering is the right solution based on a number of factors, not the least of which are feasibility from a technical and financial perspective but also supportability.
The guidance provided below is based on Exchange 2003/2000 technology and to some extent 2007 as far as server clusters, also known as single copy clusters (SCC) is concerned. There are several articles on the subject. Below are some that you may be interested in to help you along with the decision-making and implementation process:
<a href="http://technet.microsoft.com/en-us/library/bb123612(EXCHG.65).aspx">Deploying Exchange Server 2003 in a Cluster</a>
<a href="http://www.microsoft.com/exchange/evaluation/features/businesscontinuity.mspx">Exchange Server 2007 Business Continuity</a>
<a href="http://technet.microsoft.com/en-us/library/bb124721(EXCHG.80).aspx">Exchange Server 2007 High Availability </a>
That ought to be enough to get you thinking about Exchange Server clusters. If you need additional guidance, drop a byte and the call will be answered.
*** End Update ***
You'll need two servers running Windows 2003 Enterprise.
Shared storage of some sort, a SAN is preferred but shared SCSI storage will work.
You will need a total of 4 IPs on your network and two private IPs for the heartbeat between the machines.
We'll call the machines EXCH1A and EXCH1B (I like to give the nodes in the cluster the same name with a litter after it to show which node in the cluster it is. Node is another name for machine.) For the IPs we'll use 192.168.0.3 for EXCH1A and 192.168.0.4 for EXCH1B. While we go through the cluster wizard it asks us for a name for the cluster. We'll call the cluster EXCH1 and give it an IP of 192.168.0.5. Before you can setup the cluster you'll need to assign a Quorum disk to the cluster. This is the disk which holds the cluster config, and it's what the cluster uses to share information between the nodes. It doesn't need to be very large, 512 MB is more than enough. Typically it is given the drive letter of Q.
Next you'll want to setup another Resource Group on the cluster. You can name it anything, I like to use the cluster name with V01, or V02, or V03, etc after it. So I'd name it EXCH01V01. We want to create another resource group so that if exchange starts to crash the Quorum doesn't start failing back and forth between nodes. Because of what's stored on the Quorum it can take a few extra seconds to start up and that will make Exchange take longer to start up.
Then run through the Exchange installer. There should be an option to install as a clustered server during the install. It will ask you what resource group to put it in and what the virtual server name and IP are going to be. This is when you give it the name EXCH1V01 and the IP 192.168.0.6. Then run through the rest of the installer.
The IPs do not have to be sequential, but they do have to be in the same subnet. None of the IPs can be DHCP addresses. Starting in Windows 2008 Server you can use DHCP for clusters, but I would not recommend it.