HP OpenVMS 8.x manual Booting from a Different Root Directory, Emergency Booting

Value System Response

6Includes XDELTA and takes the initial breakpoint.

7Includes XDELTA, displays the SYSBOOT prompt, and takes the initial breakpoint at system initialization.

The following is an example of booting with XDELTA from fs1: at the EFI> prompt:

EFI> fs1:\efi\vms\vms_loader.efi -flags 0,7

For more information about using XDELTA, see the HP OpenVMS Delta/XDelta Debugger Manual.

A.6.11 Booting from a Different Root Directory

By default, the OpenVMS I64 operating system is installed in the system root directory [SYS0]. However, if you have created a cluster system disk, you can use the SYS$MANAGER:CLUSTER_CONFIG_LAN.COM procedure to add a copy of the operating system to a different root directory. (For more information about using the SYS$MANAGER:CLUSTER_CONFIG_LAN.COM procedure, see the HP OpenVMS System Manager's Manual .)

To boot from a different root (for example, [SYS3]), enter the following command at the EFI Shell prompt, where fsn: (such as fs1:) is the device associated with the system disk:

Shell> fsn:\efi\vms\vms_loader.efi -flags 3,0

A.6.12 Emergency Booting

If a system problem prevents your system from booting, you might need to perform an emergency boot operation. Table A-3summarizes these emergency boot operations, and the sections that follow describe each boot operation in more detail.

Table A-3 Emergency Boot Procedures

Operation	When to Use
Booting with default system parameters	When parameter values in the parameter file have been modified
	so that the system is unbootable
Booting without startup and login procedures	If an error in the startup or login procedure prevents you from
	logging in
Booting without the user authorization file	If you have forgotten the password and cannot log in to a
	privileged account

A.6.12.1 Booting with Default System Parameters

If the current values stored in the parameter file have been incorrectly modified, these incorrect values might cause the system to become unbootable. With a conversational boot operation, you can reset the active values for all system parameters to the default value. (In most cases, HP recommends that you use AUTOGEN to modify system parameters. In certain cases, however, you can use a conversational boot to modify a parameter value temporarily. To change a parameter value permanently, you must edit MODPARAMS.DAT and run AUTOGEN. For instructions, see the HP OpenVMS System Manager's Manual, Volume 2: Tuning, Monitoring, and Complex Systems.) The default values allow you to boot the system temporarily so you can correct the problem.

How to Perform This Task

1.Begin the conversational boot by entering the following command at the EFI Shell prompt, where fsn: (such as fs1:) is the device associated with the system disk:

Shell> fsn:\efi\vms\vms_loader.efi -flags 0,1

2.At the SYSBOOT> prompt, enter the following command:

SYSBOOT> USE DEFAULT

The USE DEFAULT command specifies that default values should be used for all parameters.

A.6 Booting Operations 181