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Mounting a target disk for backup of the system disk.

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Mounting a target disk for backup of the system disk.


I tried to do a backup command of the system disk to another disk (it will initialize it but that’s O.K). I booted from the CD kit and got to DCL. I then mounted both the system disk and the output disk normally and I tried thus:
backup/image/verify DKA0: DKA300:

Here I got an error saying that I must mount DKA300 with the /FOREIGN qualifier. I did that and then tried again the above BACKUP command. Here it did do the BACKUP but when I tried the normal boot of the system disk afterwards it got stuck in mounting DKA300 in SYSTARTUP_VMS.COM file. I probably have to change the mount command there to mount with the /FOREIGN qualifier or comment it out.
My questions are
1) Do I have to mount with the /FOREIGN qualifier for this backup?
2) Will a restore from backup work O.K when the mount before backup done with /FOREIGN?
3) Will it simply work by logical block numbers?
4) If I want it to be done without /FOREIGN and have also another bootable system disk that can be used also for a restore of the original system disk, how this is to be done?
5) The page and swap files, the SYS$ERRLOG.DMP and SYSDUMP.DMP will not actually be backed up but they will still have file headers and allocation in the target disk, right?

It's on Personal Alpha.

Thanks for the answers.
Honored Contributor

Re: Mounting a target disk for backup of the system disk.

For this task, have a look at the "Backing Up the System Disk" section:


from the HP OpenVMS documentation, and specifically the installation and upgrade manual. The OpenVMS documentation set is here:


As for your questions: Yes, Yes, No, via a file-oriented mount and the specification of a target saveset/SAVE on the command, Yes.

And here's one of my usual suggestions. Read the BACKUP manual. Seriously. I've been at this for over a quarter century, and I still end up reading that manual from time to time. (And I wrote part of that manual.) In particular, follow the most appropriate of the many examples provided. BACKUP syntax is complex and arcane, though the command is documented and a number of task-specific example commands are available in the HELP text and in the back of the BACKUP documentation.
Honored Contributor

Re: Mounting a target disk for backup of the system disk.

ps: you cannot have multiple volumes with the same volume label all mounted as shared.

This is the most likely trigger for the problem you had in SYSTARTUP_VMS.COM, here.

You can have duplicates so long as only one volume is mounted shared (the others being mounted privately, or not mounted), or you can use the SET VOLUME /LABEL command and change to unique volume labels.

The MOUNT information would be another good read in the documentation. MOUNT isn't nearly as arcane as BACKUP, but you can still nuke a disk with certain and selected (and incautious) MOUNT commands.
Jan van den Ende
Honored Contributor

Re: Mounting a target disk for backup of the system disk.


Hoff implied the answer, but to make it really clear:

(0 if needed). Boot WITHOUT mounting the copied system disk.
1. Mount the copied disk IN YOUR PROCESS -- ie, without /SYSTEM
2. (with privilege) $ SET VOLUME /label=
3. check: diskmount that disk & $ MOUNT it /SYSTEM
4. shutdown
5. change the boot device to DKA300
( probably by
>>> set bootdef_dev DKA300
but check the hardware manual of your system)
6. boot

--- if you have any references to DKA0 or DKA300 in your startup sequence; you must swap them before shutdown. Or better, replcae them with using Logical Names



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