HP OpenVMS Systems Documentation

Content starts here

HP OpenVMS DCL Dictionary

Previous Contents Index


Initializes the boot block on the target device.


SET BOOTBLOCK [boot-file]



Specifies the filename of the boot file for the target disk.

Architecture-specific defaults are applied for the boot file. For I64, the default is SYS$SYSROOT:[SYS$LDR]SYS$EFI.SYS (SYS$EFI).

The boot file must be contiguous. If the target boot file is not contiguous, use the DCL command COPY/CONTIGUOUS or another functionally similar mechanism to recreate a contiguous version of the boot file.

The boot file must also be marked NOMOVE (using the DCL command SET FILE/NOMOVE) to avoid a bootstrap failure that could result from the normal and expected operations of disk defragmentation tools.


The SET BOOTBLOCK command writes a boot block onto the specified disk.

As an alternative to using the SET BOOTBLOCK command, you can use RUN to invoke the SETBOOT utility, which then prompts you for all required input.


/BLOCK_SIZE=512 (default)


Specifies the target block size for the bootstrap device, in bytes.

The 512-byte block size applies for most disk devices. The 2048-byte block size typically is used only when writing the boot block to specific OpenVMS I64 CD and DVD devices.


Specifies OpenVMS I64 as the target architecture for the boot block. The default boot file for OpenVMS I64 is SYS$SYSROOT:[SYS$LDR]SYS$EFI.SYS.

/PRESERVE=keyword (default)


/PRESERVE=SIGNATURE maintains the existing GUID disk signature value. The default is to generate a new signature for the target volume.

Previous Next Contents Index