Dumping Images of my VAX-11/730's Drives?

[Mark J. Blair]

> On Mar 8, 2016, at 15:21, Peter Coghlan <cctalk at beyondthepale.ie> wrote:
> 
> If you get TCP/IP networking like Multinet (ie not like CMUIP) running, you
> should be able to use FTP, rcp or maybe even TFTP to move a VMS BACKUP saveset
> to another system.  The snag is you need enough scratch space to create the
> saveset on the 11/730 before you transfer it.

Well, there's the problem: I don't have scratch space, since all of the hard drives are precisely what I want to image.

> C-Kermit for VMS might be able to do this - I can't recall.

Getting it onto the machine in the first place might be a challenge!

> 
> If you mount /foreign your non-system disk, it should be accessible at a logical
> block level instead of at a file level.  VMS BACKUP won't like this but COPY
> should just copy logical blocks from the foreign mounted device.  This probably
> isn't very useful to you but rcp or FTP PUT might also similarly cope with a
> foreign mounted devices and this may be another way of generating a raw dump
> of the device, provided there are no errors on it.  (There may be issues
> detecting the size of the device and the operation may end with an error when
> no more blocks can be read.  If whatever software you use doesn't try to
> discard it's output on encountering an error, all should be well.)  However,
> you can't mount your system disk /foreign.

I can boot either 7.3 from the R80 fixed drive, or 5.2 from an RL02 pack. So in theory, I should be able to boot from each of them to image the other. There might be TCP/IP support on the 7.3 installation, but I doubt there's any TCP/IP support on the 5.2. I hope that the DECNET support is there on both installations for the ethernet card.

I set up a VM on my Mac running Ubuntu with DECNET support installed. Despite being orphaned several years ago, it still seems to run. So I think that trying to bring up DECNET on the VAX might give me options. I was thinking that if nothing else, if I can log into the VAX remotely via DECNET and log the terminal output, then maybe I could just DUMP a foreign-mounted volume and then write some throw-away program to transmogrify the hex dump into a block-level image. It would be slow, but I hope it would at least be quite a bit faster than dumping over an async serial port.

If I can write a file from the VAX to that Ubuntu VM via DECNET, then maybe I can just COPY a foreign-mounted volume to a file on the VM. I don't know what capabilities the Linux DECNET support gives me yet, but if I can do this then that should be a good option. I wonder if I can image tapes that way, too?

> 
> Another way would be to write some code (VAX MACRO assembly / C / FORTRAN /
> BASIC or whatever compiler you have to use VMS system services like SYS$ASSIGN
> and SYS$QIO to read logical blocks from the disks and do something sensible
> when errors are encountered.  This might involve a steep learning curve and the
> results will probably not be as well optimised to the task as VMS BACKUP.  It
> should be possible to find some sample code to do something like this.

I hope I don't have to go to that much effort, particularly since I don't know if there are any language compilers/assemblers on the system, and I want to image the drives before I monkey around with the system much.

> Clustering is pretty simple when you know how but if you don't want to get into
> configuring a cluster, a DECnet connected system or emulated system would
> probably be the way to go.  Configuring DECnet on VMS can be done very easily
> with surprisingly little understanding of what is going on and is less invasive
> than configuring a cluster.

You had me at "surprisingly little understanding of what is going on"! This sounds like the thing for me to try next.


> On VMS, any file, including a BACKUP saveset can be specified as being located
> on a remote DECnet node, so it is possible to run BACKUP on your 11/730 and have
> the output saveset situated on a different VAX / Alpha / Itanium / emulated
> system running VMS or on a unix or other system capable of running DECnet well,
> (ultrix?), even a PC/Macintosh running DOS/Windows/Macos and DEC Pathworks.

That sounds very promising!


> If your 11/730 is already configured to be a cluster member (if it says
> something like "Waiting to form or join a VAXcluster" on the console at boot
> time and then pauses for while before continuing) then you probably don't have
> to do anything further to it to make it function as part of a cluster.  The
> only experimentation required would be on the additional cluster member, which
> could be an emulated system using simh for example if you don't have any other
> suitable hardware available.  Once you are clustered, you can access disks on
> a remote cluster node as if they were local.  Clustering with an emulated
> system would be especially suitable for producing raw block copies of the
> disks on the 11/730 on the filesystem of the system hosting the emulation.

Hmm, I don't remember whether it output any messages like that, and I don't recall where the console printouts are from my successful boots of the system. I'll look for this next time I bring up the system.

Thanks for all of the suggestions! I still have a lot of learning curve to climb in the VMS world.


-- 
Mark J. Blair, NF6X <nf6x at nf6x.net>
http://www.nf6x.net/