After reading through the SQL Server 2005 Upgrade Technical Reference Guide, you should have a good idea about which direction you want to move forward. The upgrade path and upgrade method will help you modify your plan so that you have the best chance to succeed. Depending on your environment, your choices may already be made for you. Regardless of whether or not you are doing an In-Place or a Side-by-Side upgrade, it will be very beneficial for you to do some testing before you flip any kind of switch to go live with SQL 2005.
In the best of scenarios, you can find another server that you can use to do testing and simulate what the environment will look like. If you cannot find another server that can be used solely for this purpose, maybe you could look at using virtualization to meet this need. You probably will not be able to simulate the hardware completely, but it should be better than nothing. Setting up a virtual instance is beyond the scope of this article but it should be fairly easy to set that up with resources found online. VMware and Microsoft both have virtualization software that can be used for free.
Scalability Experts has a tool called SQL Server Upgrade Assistant 2005 that can be used to verify how your applications will run against SQL Server 2005 instead of 2000. Even if you do not use this tool, by reading through the User Guide you can develop your own plan for testing and that should help you discover the items you need to address.
In the fourth part of this series, I’ll describe some things you should consider as you are setting up your new server.