IBM SY44-5902-05 manual Continuously Powered Main Storage CPM, Getting started

Continuously Powered Main Storage (CPM)

Continuously powered main storage applies only to models 6xx, 7xx, SB1, S10, S20, S30, and S40. When utility power is lost or a thermal fault occurs on a model with System Power Control Network (SPCN), the system applies power from the internal batteries (BBU) to the main storage cards. This process is known as continuously powered main storage (CPM).

CPM increases system availability. It provides full operating power for a short time to allow a system shut-down procedure to run. This situation is indicated by a D6xx xxxx SRC on the control panel display. When the system is powered down, CPM then maintains power for a varied amount of time (for example, one day) only to the main storage cards.

CPM allows the customer data to be stored and minimizes recovery time. When normal power returns, the system brings the battery-stored data into disk storage, loads the Licensed Internal Code, and performs an IPL.

Note: For the system to automatically perform an IPL after a power loss, you must select Normal or Auto mode and set the system value QPWRRSTIPL to the allow option.

CPM is available automatically at each IPL and is enabled only when utility power is lost or a thermal fault occurs. It might be necessary to disable CPM to perform a specific repair on the system.

Low-level debug and data collecting procedures

Introduction

Use these procedures to collect data for problems with Licensed Internal Code or hardware that you have been unable to solve with other methods.

The low-level debug functions (Functions 54-64) use subfunctions. This means that these functions have a function range inside them (00-FF) where you can display or enter information.

Getting started

Before you start, ensure that Manual mode is selected.

To enable the low-level debug functions, perform the following steps:

1.At the control panel, select function 25.

2.Press Enter on the control panel.

3.Press the Increment (↑) button again. The number 26 appears in the Function/Data display.

4.Press Enter on the control panel. The low-level debug functions are now enabled.

Displaying data for functions 54 through 58, 63, and 64 (Models 150, 170, 250, 4xx, 50x, 51x, 530, 53S, 6xx, 7xx, SB1, and Sxx)

Use this procedure to collect data. Each function has a different amount of data to collect. Collect the data for the range that is listed for each function in the

Chapter 4. Service Reference Procedures 131