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How can i access backup tape created on open vms 7.1.1-1H1 platform from RHEL5

biswajit_1
Occasional Visitor

How can i access backup tape created on open vms 7.1.1-1H1 platform from RHEL5

Recently I have faced a problem on the virtualization of OpenVMS 7.1.1-1H1 to a windows computer with the help of freeaxp. In our power plant we use OpenVMS 7.1.1-1H1 (hp makes) as an operating system and to control the process we use PMS 2.2 (ABB MAKE) which is an application on OpenVMS. I have taken an image backup (.bck format) of the SCSI hard disk of OpenVMS (actually PMS hard disk, disk dka0 which is bootable) with the help of the following command

Backup/image/ign= (label, noback)/media=comp dka0: mkc500:u1ws1p.bck/save/rew/lo


Where mkc500 is a SCSI tape drive.

Now I have connected this tape drive with tape in a computer, operating system is RHEL5. This SCSI drive detected as st0. Next I have given these two commands

Mt –f /dev/st0 fsf
DD if=/dev/st0 bs=8192 of=/mnt/u1ws1p.bck

But I found that in MNT the size of the .bck file was kb range something like 614kb.
I think that was header file .But the data file must have been in GB range.My requirement is to copy the .bck file to the hard disk using linux.
5 REPLIES
Hoff
Honored Contributor

Re: How can i access backup tape created on open vms 7.1.1-1H1 platform from RHEL5

To answer your direct question, here's a tool which can read BACKUP savesets, and some instructions on the page and within the source code of the tool:

http://labs.hoffmanlabs.com/node/817

It hasn't been heavily tested with magtape:

A typical foreign-mounted OpenVMS BACKUP magtape uses ANSI tape labeling, so you'll get a few smaller blocks for the headers, and then the blocks of the saveset data.

RHEL won't be able to interpret various of the RMS file formats found in the tape (once you get the files copied off the tape via vmsbackup or whatever other means used) as there's no RMS layer available outside of VMS. You're basically seeking to peek into SQLite or MySQL or other database files without access to the database software. So getting at the contents of these VMS files over on RHEL or on Windows is reverse-engineering a block data dump. Even the common sequential file formats (eg: VFC format) used on VMS will require some conversion effort.

As for your RHEL questions reading ANSI-labeled tapes, I'd suggest an RHEL forum here; outside of the BACKUP format and origin of the tape, your questions and your issues and your commands will be entirely those of RHEL.

I would recommend finding somebody around that has the equipment and the knowledge to transfer this data for you, as the approach you're following here is difficult. At best. And I know VMS, BACKUP and Unix.

It is vastly easier to get the bulk of this transfer work done on VMS, whether the goal here is the relocation of the data to another OS platform (a port off of VMS) or a port over to an emulated environment. That's because VMS can read these files. Directly.
Volker Halle
Honored Contributor

Re: How can i access backup tape created on open vms 7.1.1-1H1 platform from RHEL5

biswajit,

please describe, what you are trying to accomplish. I see the word 'FreeAXP' in your question. Can we assume, that you want to emulate/virtualize your OpenVMS Alpha system by running FreeAXP on a RHEL system ?

If that's the case, the easiest way to get the backup over to the FreeAXP system is with an image-backup via DECnet. Install OpenVMS from CD onto FreeAXP, configure DECnet and a big disk to hold the saveset and use BACKUP/IMAGE DKA0: node::dev:u1ws1p.bck/save

I assume FreeAXP does not support physical tape access. The Avanti product might support directly connected SCSI tapes. This would be another possibility.

Volker.
Joseph Huber_1
Honored Contributor

Re: How can i access backup tape created on open vms 7.1.1-1H1 platform from RHEL5


and before You attempt to make another backup to a saveset on disk, be aware that
Backup/image/ign=(label, noback)
might not produce a bootable image, but probably wastes space with the ignore=nobackup option!
Better do an ignore=(interlock), if it is not possible to do a "standalone" backup.

You did not say if You have already a freeaxp system running or just have to build one from the image saveset:
If You do not already have a bootable virtual disk for freeaxp, then a saveset does not help much, it is not bootable.
Initially You either need a bootable VMS CD or a VMS disk-image (built with LD on VMS). Such disk-image can then be transferred to the freeaxp host system and booted.
Only after having a virtual bootable disk on freeaxp You can handle backup savesets on that system.
http://www.mpp.mpg.de/~huber
Joseph Huber_1
Honored Contributor

Re: How can i access backup tape created on open vms 7.1.1-1H1 platform from RHEL5

And if You really need to transfer via tape: here is a Linux howto for Ansi formatted tapes:
http://tldp.org/HOWTO/VMS-to-Linux-HOWTO/x838.html

And a caveat I posted on a similar question:
http://www.computing.net/answers/openvms/grab-openvms-save-set-from-tape-in-linuxwin/617.html
http://www.mpp.mpg.de/~huber
Bill Pedersen
Regular Advisor

Re: How can i access backup tape created on open vms 7.1.1-1H1 platform from RHEL5

biswajit:

From what you have discussed and from the description of what you have done it sounds as if you are trying to make a bootable image of your system disk from the OpenVMS/PMS environment.

If you do not have FreeAXP running on RHEL5 and knowledgable of the tape drive and the container files you will be using to emulate the disks from your "real" OpenVMS system you probably can not make the container file you seek.

FreeAXP as well as SIMH and Charon-VAX/Charon-AXP all use container files which are nothing more than block for block equivalents of the disks they are emulating. So using BACKUP in just about any mode will not get you what you want.

Given that you have been using FreeAXP it suggests your PMS environment is actually an Alpha...

Do you have OpenVMS running on FreeAXP on RHEL5? Have you been able to configure it to access the SCSI tape drive? If so you can move forward with creating the container file and then restoring the BACKUP save set. But as noted, you may have not make a bootable "image" and might need to consider a different backup command and then restore.
Bill Pedersen
CCSS - Computer Consulting System Services, LLC