The following sections describe how to set up automatic booting, set and show the default boot device, modify boot parameters, and create a bootable OpenVMS Alpha system disk using the Writeboot utility.
Alpha computers can boot automatically from a designated boot device. When you installed the OpenVMS Alpha operating system, you designated the system disk as the default boot device. Section describes how to change the default boot device.
Alpha computers can boot automatically from the default boot device under the following conditions:
Set the system to boot automatically by performing one of the following steps:
| IF ... | THEN GO TO... |
|---|---|
The OpenVMS Alpha operating system is running | Step 1 |
The OpenVMS Alpha operating system is not running | Step 4 |
Enter the following command and press Enter:
$@SYS$SYSTEM:SHUTDOWN
Answer the questions displayed by the system. When the procedure asks whether an automatic reboot should be performed, press Enter for NO. When the procedure is finished, it displays the following message:
SYSTEM SHUTDOWN COMPLETE
Halt the system by pressing either Ctrl/P or Halt. (See Section for more information about how to halt your Alpha computer.)
If you have an SMP system with multiple CPUs, enter the following command at the console prompt (>>>) to stop the other CPUs:
>>>INITIALIZE
Enter the following command to show whether the system has been set to boot automatically:
>>>SHOW AUTO_ACTION
The system displays one of the following:
Enter the SET AUTO_ACTION command if you want to change the automatic booting behavior. HP recommends that AUTO_ACTION be set to RESTART. This forces the system to attempt to write a crash dump to the dump file, and after the dump write completes, the system tries to reboot itself automatically. For example, the following command sets the system to reboot automatically:
>>>SET AUTO_ACTION RESTART
After you set this variable, HP recommends that you set the boot device and operating system flags as well, using the SET BOOTDEF_DEV and SET BOOT_OSFLAGS commands described in the following sections.
Use the SET BOOTDEF_DEV command to tell the system which drive you want to boot from (that drive becomes the default boot device). Use the SHOW BOOTDEF_DEV command to display the current default boot device.
Note that when you set this variable, HP recommends that you set the operating system boot parameters as well, using the SET BOOT_OSFLAGS command.
At the console prompt (>>>), enter the SET BOOTDEF_DEV command in the following format:
Substitute the device name of the system disk for device-name. For example, to boot from a drive with a device name of DKA400 on a DEC 3000 Alpha series computer, enter the following command and press Enter:
>>>SET BOOTDEF_DEV DKA400
The next time you boot the system, you can enter the BOOT command without specifying a device name (because DKA400 is now the default boot device). For example:
>>>BOOT
NOTE: If you have not used the SET BOOTDEF_DEV command to set the drive to boot from and you enter the BOOT command without specifying a device name, the system displays an error message. | |
Use the SHOW BOOTDEF_DEV command to find out what drive was specified in the last SET BOOT command. For example:
>>>SHOW BOOTDEF_DEV
To cancel the drive specified in a previous SET BOOTDEF_DEV command, enter the following command and press Enter:
>>>SET BOOTDEF_DEV
NOTE: This command is not valid on DEC 3000 Alpha series systems. | |
By default, when you boot the operating system, the flags parameter is set to 0. If you want to define parameters to enable specific functions during the booting process, use the SET BOOT_OSFLAGS console command.
The following is a list of values you can specify with the SET BOOT_OSFLAGS command.
NOTE: HP recommends that you keep the BOOT_OSFLAGS parameter at the default value 0 unless you have a specific need to change it (for example, to troubleshoot a system boot problem). | |
| Hexadecimal Value | System Response |
|---|---|
1 | Allows a conversational boot (the system displays the SYSBOOT> prompt). |
2 | Maps XDELTA to a running system. |
4 | Stops the boot procedure at the initial system breakpoint. |
8 | Performs a diagnostic bootstrap. |
10 | Stops the boot procedure at the bootstrap breakpoints. |
20 | Omits header from secondary bootstrap image. |
80 | Prompts for the name of the secondary bootstrap file. |
100 | Halts the system before the secondary bootstrap. |
2000 | Marks corrected read data error pages as bad. |
10000 | Displays extensive, detailed debug messages during the boot process. |
20000 | Displays selected user-oriented messages during the boot process. |
The following examples show how to use the SET BOOT_OSFLAGS command:
The following command specifies the root directory as 0 and the parameter as 1, which sets the system to perform a conversational boot from the [SYS0] directory when you enter the BOOT command:
>>>SET BOOT_OSFLAGS 0,1
The following command specifies the root directory as 1 and the parameter as 0, which sets the system (for example, the second host in a two-system DSSI OpenVMS Cluster configuration) to boot from the [SYS1] directory (instead of [SYS0]) when you enter the BOOT command:
>>>SET BOOT_OSFLAGS 1,0
The following example specifies the root directory as 0 and the parameters as 1, 2, 4, and 20000 (for a total hexadecimal value of 20007). As a result, when you enter the BOOT command, the system performs a conversational boot from the [SYS0] directory with XDELTA, stops at the initial system breakpoint, and displays relevant user messages.
>>>SET BOOT_OSFLAGS 0,20007
To display the parameters you have just set, use the SHOW BOOT_OSFLAGS command. For example:
>>>SHOW BOOT_OSFLAGSBOOT_OSFLAGS = 0,20007
Now that the boot parameters have been set, to boot the system using the parameters you have specified, simply type BOOT or B at the prompt (>>>).
The boot block is block 0 of the system disk. It contains the size and location of the primary bootstrap image (APB.EXE) used to boot the system. If you suspect that the boot block on your system disk is invalid, you can use the Writeboot utility (WRITEBOOT.EXE) to write a new boot block.
The Writeboot utility is copied to your system disk during the installation procedure. It enables you to create a bootable OpenVMS Alpha system disk from one that was originally created by one of the following methods:
The Writeboot utility also enables you to rewrite the boot block of an OpenVMS Alpha system disk to point to a new version of the OpenVMS Alpha primary bootstrap file (APB.EXE) that you have previously copied to the disk. (Note that the file must be contiguous.)
NOTE: The file must be contiguous and movefile operations on the file must be disabled. If the file is not contiguous, use the DCL command COPY/CONTIGUOUS (or similar) to re-create a contiguous version of the file. To disable movefile operations, use the DCL command SET FILE/NOMOVE. This prevents bootstrap failures that could result from the normal and expected operations of disk defragmentation tools. | |
To start the Writeboot utility, enter the following command:
$RUN SYS$SYSTEM:WRITEBOOT
The utility prompts you as follows:
Update VAX portion of boot block (default is Y): Update Alpha portion of boot block (default is Y):
Answer N (NO) to the VAX prompt. If you answer Y (YES) to update the Alpha boot block, the utility prompts you for the Alpha boot file:
Enter Alpha boot file:
Specify device-name:[VMS$COMMON.SYSEXE]APB.EXE
in response to this prompt, where device-name indicates
the device on which the system disk is mounted. The utility writes
the specified information to the boot block on the system disk. For
more information, see the HP OpenVMS System Manager's Manual, Volume 1: Essentials.