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[OT] Re: Hercules - how to get a zVM OS (legally bought!) and put it on a VM under Hercules?



On Sat, 22 Aug 2015 05:25:02 -0400 (EDT), Christian Boitet wrote:
> 
> sorry if this goes to the wrong group...
> if so, please give us a better pointer.

This is a forum for those running the s390x port of Debian.  How to run Debian
under Hercules would definitely be on-topic here, since Hercules is a software
emulation of the hardware on which Debian for s390x was designed to run.
If your question regards how to run Debian in a virtual machine under z/VM,
that would also be on topic.  But questions about how to run z/VM under Hercules
are not on topic.  I would suggest the Hercules forums on Yahoo, specifically,

   https://groups.yahoo.com/neo/groups/H390-VM/info

> 
> We have a z800 with zVM 5.3.0, and under it several Linux/390 (Debian)
> virtual machines, and a special VM that runs zVM 4.2.0 and under it a
> legacy system made of 100 or more VMs, all under CMS, plus of course
> all service VMs.
> 
> We have bought the 4.2.0 system "one shot" back in 2001 and have been
> entitled to all following releases, including the 5.3.0.
> 
> Now, this z800 is a burden, the processor went dead last year and we
> had to find a second-hand one...
> 
> In short, we would like to put all our configuration under Hercules,
> preferably on a Macintosh under Yosemite.
> 
> Our problem is: how to get our OSs (zVM 530 and zVM 420) from our
> machine and install them under Hercules?
> 
> Thnks in advance for any help!

Although this question is, strictly-speaking, off topic, I suspect that it
is of interest to many of the subscribers to this list, so I'll answer it
anyway.

I need to start by saying that I am not a lawyer, an IBM employee, or an
official spokesman for any person, company, or government.

As I see it, there are three sides to this question: the practical side,
the legal side, and the technical side.  I will address them in that order.
First, the practical side.  Hercules is a software emulation of a mainframe,
not a real mainframe.  It adds a tremendous amount of overhead.  Debian
under Hercules under amd64 is *way* slower than Debian running directly
under amd64 using the same hardware.  I suspect you will find that
the performance of your z/VM systems is not adequate for production use,
even when Hercules is running on the fastest amd64 processors available.
But the only way to find out is to try it, I suppose.

Next is the legal side.  As I said, I am not a lawyer.  But if you check
the fine print in your contract, you may find that you did not, strictly
speaking, *buy* z/VM.  What you probably did was *license* z/VM.  Typically,
this license is good for a single mainframe box.  The license is typically
not transferable to another box without a contract modification.
IBM typically does not license their proprietary 64-bit mainframe operating
systems, such as z/VM, to run on anything other than IBM hardware.  I'd
have your legal department go over this very carefully, if I were you.
I'd hate to see you get in legal trouble for running z/VM on a processor
for which you are not licensed.

Finally, there's the technical side.  There are a number of ways to migrate
the data.  One way that I can think of is to use DDR to create a volume
dump, convert the real tape file to an AWS emulated tape file, create
a DDR stand-alone IPL tape, convert that to an AWS emulated tape file,
Then IPL the DDR stand-alone IPL tape under Hercules using the AWS emulated
tape file, and use the stand-alone version of DDR to restore the dumped
volume from its AWS emulated tape file to a Hercules volume.  That's one
way to do it.  Perhaps the folks on the above Yahoo group know a better way.  

Regards,

-- 
  .''`.     Stephen Powell    <zlinuxman@wowway.com>
 : :'  :
 `. `'`
   `-


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