Never forget that computers are machines. They have no common sense and possess no trace of intelligence. They require help from a human being whenever a problem arises. Still, i5/OS contains a certain amount of forethought that was carefully programmed by IBM. The system can usually help you solve even severe problems.
Severe trouble can be arbitrarily defined as the kind of trouble that renders the entire system nonoperational.
You can avoid trouble caused by power failures by purchasing an uninterrupted power supply (UPS) unit and connecting it between the raw utility power supply and the system.
If the power fails and you do not have a UPS unit, or the UPS unit did not work, you cannot do much until power returns. You might place a rush order for a UPS unit or call for repairs of your existing UPS.
When power returns, IPL the system. If the system was busy when the power failed (which it almost certainly was), this IPL will take much longer than usual because the system needs to rebuild the access paths of database files that were open when the power failed.
Once IPL completes, you should ask your users to return to whatever they were doing before the power failure and make sure that the last transaction they entered was recorded. If you do not use commitment control, there is a good chance that data may be lost.
If your system freezes up (i.e., it doesn't respond to input s any display station), go to the control panel on the CPU. The Data windows should have an eight-character system reference code (SRC), such as B900 3004. The System Attention light might also be lit.
IBMs Info Center contains problem summary forms. Print the appropriate form from the Web site (Chapter 17 describes how to get online manuals). Complete the form you printed, describes the problem, and indicate which control panel lights are on. Write down the SRC shown in the Data windows. Be sure to jot down the date and the time when the system froze. Then call IBM for hardware support.
The i5 Basic System Operation Manual contains detailed instructions about what you can or should do in cases of severe trouble.