HP OpenVMS 8.x manual Writing a New Boot Block

A.5.3 Writing a New Boot Block

The boot block structures on the system disk contain the size and location of the boot partition and other details relevant to the bootstrap of OpenVMS I64. The size and location of the boot partition stored within the boot block structures must be maintained and must reference the current location of the OpenVMS file SYS$EFI.SYS.

Current versions of BACKUP maintain the boot block structures as well as the size and location of the boot partition during image operations (analogous to the similar BACKUP/IMAGE operations that maintain the boot block on OpenVMS Alpha disks). Older versions of BACKUP do not maintain these structures and do not correctly locate core OpenVMS I64 bootstrap files.

If the boot partition file SYS$EFI.SYS is manually replaced or relocated, you must use the DCL command SET BOOTBLOCK or the SYS$SETBOOT image to rewrite the boot block structures. The SET BOOTBLOCK command and SYS$SETBOOT are analogous to the OpenVMS Alpha Writeboot utility; they provide OpenVMS I64 with the equivalent of what the Writeboot utility provides on OpenVMS Alpha.

NOTE: Do not use the OpenVMS Alpha Writeboot utility to rewrite boot block structures on an OpenVMS I64 system disk.

The SET BOOTBLOCK command enables you to establish the boot block pointers necessary for the EFI console to find and bootstrap an OpenVMS I64 system disk. You must use this command if the target OpenVMS I64 system disk was originally created by one of the following methods:

•A version of BACKUP that does not support the OpenVMS I64 system disk structure. HP recommends that you do not use these versions of BACKUP for archiving or restoring an OpenVMS I64 system disk.

•A nonimage backup of an OpenVMS I64 system disk (possibly corrupting the boot block and various directory backlinks that must be manually reset). HP recommends that you do not use nonimage backups.

•A nonimage restore of an OpenVMS I64 system disk from an image save set. HP recommends that you do not use a nonimage restoration.

170 Configuring OpenVMS I64 Hardware Operation and Boot Operations, and Booting and Shutting Down Your System