topic Re: OpenVMS I64 image backups in Operating System - OpenVMS

OpenVMS I64 image backups

Max Bruno Jarvis — Wed, 11 Feb 2009 10:48:56 GMT

I used BACKUP /IMAGE to make a copy of my OpenVMS I64 system disk on an Integrity server rx2660. I booted from the OpenVMS DVD to run this copy, so I wasn't trying to copy the running system disk. The copy appears to complete OK, but my problem is that the copy disk won't boot in the same way as the original.

I can boot from the copy disk using EFI's "boot from file" option, then use the boot_options command file to "validate" (and correct) the EFI boot list entry for the copy disk, and then it works properly. Is it normal to have to do this to create a bootable copy of the system disk?

I'm wondering whether the EFI boot list entry contains some information about the whereabouts of some file on the disk, and after the disk has been the target of BACKUP /IMAGE, that file is in a different place?

Any help gratefully received. Thanks.

Re: OpenVMS I64 image backups

Guy Peleg — Thu, 12 Feb 2009 07:15:28 GMT

Short answer - yes it is normal.

Here is the longer answer....

The EFI stores the GUID (Global Unique
Identifier) of each boot option. It is
a 128bit (I think!) binary number that
uniquely identifies the boot partition.
The same number is stored inside the boot
block on the system disk.

When the EFI attempts to boot using a boot
option a check is made to compare the GUID
stored in the console to the one stored on
the disk. If there is no match, the boot option will not work.

When restoring a BACKUP/IMAGE, the backup
utility calls $SETBOOT to create the boot
block on your new system disk. $SETBOOT
generates a new GUID so the one stored in
the console does not match the one stored
in the EFI and you have to re-validate
the boot option.

While working in HP, I have modified BACKUP
to preserve the GUID inside the save-set
header, what is currently missing is a
mechanism for BACKUP to pass the GUID to
$SETBOOT and instruct $SETBOOT to avoid
creating a new GUID.

So what you are seeing is normal behavior
(or at least expected).

Guy Peleg
Maklee Engineering
http://www.maklee.com

Re: OpenVMS I64 image backups

Robert Gezelter — Thu, 12 Feb 2009 07:45:51 GMT

Max,

Indeed, a GUID is 128 bits (the Wikipedia entry for GUID is at http://en.wikipedia.org/wiki/Guid , which also contains links to entries about how EFI uses GUID.

- Bob Gezelter, http://www.rlgsc.com