System Startup, Configuration, and Shutdown Reference Manual (32650-90892)

22 Chapter2

Initiating System Activity

Resetting the System

There are two general types of resets for the HP 3000 (Series 900): a soft reset and a hard

reset.

Soft Reset

A soft reset, the type of reset used most often, preserves the current processor state. This

type of reset performs a nondisruptive memory test and terminates all I/O operations

before executing recovery software for starting the boot device and console selection

process. A soft reset can also occur during a software reboot at the completion of a bootable

ISL utility, such as INSTALL, UPDATE, or DUMP.

More information on issuing resets from the console is provided later in this chapter.

Hard Reset

A hard reset is disruptive. It initiates the processor self-test that resets memory and

terminates all I/O operations. A hard reset is necessary after a hardware failure or after an

error from which the system cannot recover.

A hard reset is initiated when the CPU is powered on. If the system is powered on already,

then entering the reset command, RS, at the system console initiates the hard reset

process.

More information on issuing resets from the console is provided later in this chapter.

Resetting the System Using the Console

With the release of the A and N-class systems, MPE supports two different types of access

into the system service ports. For NIO based systems, the console interfaces with the 900

Series HP 3000 through the access port (AP) located in the channel I/O (CIO) section of the

system card cage. For A and N-class systems, the Guardian Service Processor (GSP)

provides access through the core I/O card.

In addition to providing other features and commands, both the GSP and the AP allow the

system manager or system operator (OP capability) to issue hard or soft resets from the

console keyboard instead of using the front panel reset switch. (The system is secured from

anyone accidentally entering an GSP/AP command. It responds to GSP/AP commands only

when the console is placed in control mode by entering

CTRL B.)

The access port supports two, two-character commands for resetting the system, as

described in Table 2-1..

Table 2-1. AP Reset Commands

Command Description

RS Reset SPU (hard reset). This command initiates a processor self-test that resets

memory and terminates all I/O operations. Do not use this type of reset in

preparation for a dump.