SQL Server has a variety of options to improve availability, including failover clustering. Failover clustering protects you from several kinds of hardware and software failures, such as a server crash, a local disk drive failure, or an application fault. Teamcenter fully supports having a clustered instance of SQL Server as one of the technologies to improve your availability.
The first consideration for failover clustering is which version of Windows Server are you going to use. Failover clustering has improved significantly in the latest versions of Windows Server, and I strongly recommend that you use Windows Server 2008 R2. However, failover clustering has been supported since the Windows NT days, so any currently supported version of Windows Server will work. You can choose either Windows Server Enterprise or Windows Server Datacenter to get clustering support.
Don't be confused by the fact that SQL Server Standard supports failover clustering (two nodes). You will still need Windows Server Enterprise or Windows Server Datacenter to get Windows support for clustering. As noted, SQL Server supports failover clustering in SQL Server Standard, SQL Server Enterprise, and SQL Server 2008 R2 Datacenter.
Older versions of Windows required the use of hardware that was approved in advance on a Hardware Compatibility List, or HCL. With the latest versions of failover clustering in Windows, you no longer need to be so picky with your hardware choices. Use what seems appropriate to get the job done. You just have to make sure that the Validate a Configuration Wizard is happy with your hardware setup when you're done configuring your hardware. You will need to have at least one (but realistically several) shared disk resources, either attached through iSCSI or on a SAN. You can read more about Windows clustering configuration and technical information in the following Microsoft white paper:
Failover Clustering in Windows Server 2008 R2
One important note: As you set up your Windows cluster, complete the setup of the MS DTC resource, because SQL Server will use it for distributed transactions.
SQL Server 2008 had a significant update to the setup experience for failover clustering, giving you more choices about how to approach your setup. Technically, you don't have to wait until the Windows failover cluster setup is complete, but I urge you to validate your cluster first before you install SQL Server. The risk of setting up SQL Server incorrectly and having to start over isn't worth waiting until the Windows cluster is installed correctly.
To install a failover cluster, follow these steps:
1. Start SQL Server Setup.
2. Accept the warning that the setup may not be compatible with Windows.
3. On the left, click Installation.
4. On the right, click New SQL Server failover cluster installation (see the screenshot below).
5. For each additional node (computer) in the cluster, run the Setup program again, but click Add node to a SQL Server failover cluster.
Important: If you are installing SQL Server 2008, run the Setup program for SQL Server 2008 Service Pack 1 to install the Setup support files. If no other instances of SQL Server are already installed, the service pack will find nothing else to update. Then, run the Setup program from the original SQL Server 2008 DVD. This will install critical updates to the Setup program that will ensure a smoother setup experience for the failover cluster.
The setup of the failover cluster will otherwise flow like a typical SQL Server setup, with a couple of caveats. You will need to create a new logical computer name when you install a cluster. Many organizations have naming standards for their servers, so be prepared to create a logical computer during the SQL Server setup process. You will want to use fixed IP addresses for server installations, so you'll need a fixed IP address for each network card that is installed on your servers in the cluster. For more information, read the following Microsoft white paper:
SQL Server 2008 Failover Clustering
Most people who first try to install a failover cluster are somewhat intimidated. Don't be afraid to try it, but do read the documentation and the white papers, and don't be afraid to reach out to the community and your favorite SQL Server consultant for help. (You can also post your comments here.) In the next post about this topic, we'll look at the unique aspects of administering a clustered SQL Server installation to help prevent you from breaking your server.
Richard Waymire is a mentor with Solid Quality Mentors and a former member of the Microsoft SQL Server development team. He has been working on SQL Server for more than 15 years, is a contributing editor of SQL Server Magazine, and is the author of several books about SQL Server. http://www.richardwaymire.com/