3.6.0 MxDB for SQL Server Installation and Administration Guide (5697-7088, December 2007)

Chapter 8: Upgrade Production SQL Servers 118

• When to upgrade? Query users for the best time to perform the

upgrade, and consider a time window in which availability

requirements are less strict.

• What if something goes wrong? You will need to determine what is a

valid machine state, and how to back it up and restore it in the

minimum amount of time. Also ensure that all support agreements

are in place and that contact information is updated.

• Will other components in the machine be affected? For example, a

SQL service pack upgrade to one instance affects all other instances on

the same machine.

2. Test the Upgrade

It is important to run the upgrade in a test environment to ensure that the

upgrade will function successfully on the production server. Testing also

ensures that there will be no surprises during or after the upgrade.

For example, to test a SQL server upgrade, you should create a typical

workload mix of your application’s user transactions and then measure

different machine parameters such as CPU or I/O load. When the test

environment is ready, complete these steps:

1. Test the current configuration and create a baseline of the results.

2. Record the start time and then perform the upgrade on the test

machine.

3. After the upgrade, check the event log and setup files for errors.

4. Record the end time to get an estimate of total down time.

5. Run the workload tests again and compare the results with the

baseline.

We recommend that the test machine be identical to the production

machine. For example, the two machines should contain the same

components (including third-party applications such as anti-virus

software) and the same settings (such as the /3G flag in boot.ini).