Performance tuning guidelines and expectations

Performance tuning is not a one-time task but an ongoing effort. Because the system environment and client workloads change, you must continually monitor and periodically tune the solution.

Because the performance of an IBM Spectrum Protect™ solution can be affected by so many factors, make changes in a controlled way. Evaluate the effects of the changes that you introduce by collecting appropriate measurements before and after changes.

For example, the following approach can be effective:

  1. Track performance of the solution over time by establishing an initial baseline of measurements of operational performance. Periodically collect the same measurements and compare the results.
  2. Implement a method to track all changes that are made to the IBM Spectrum Protect solution.

    Use strict change control to help you understand the performance impact of any change.

    Limit the changes that you make at one time so that you can more easily determine what makes a difference.

  3. After a change and before you make further changes, observe system operations and performance over enough time to evaluate the full effect of the changes.

    Observe the system over a time span that is based on typical cycles of operations. For example, if you always have a once-a-week peak in client backup operations, be sure that peak time is included in your observations.

  4. Evaluate the results before you make further changes.

Most performance tuning yields limited improvements. Carefully consider how much time is reasonable to spend on improving system performance. Service Level Agreements are an excellent way to set performance goals.

Running a system near its limits can have negative consequences. In such a case, 10 percent more workload might degrade response times dramatically more than an expected 10 percent. In this situation, you must determine which component or process is the bottleneck and eliminate it.

After a system is properly tuned, improving system performance can be achieved only by reducing the workload or adding appropriate resources. You might have to revise your goals and expectations. For significant performance improvements, you must find the bottleneck and then consider one or more of the following actions: