?

?

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Fish Fish
Sent: 26 October 2022 05:30
To: [email protected]
Subject: Re: [h390-vm] Do I have a looping issue?

Jim Snellen wrote:

I am running VM/370 with DOS/VS as a guest machine and MVS 3.8J TK4-
as a guest machine. I use HercGUI

Which should not make any difference.

and Hercules version 4.4.1.10647-SDL-gd0ccfbc9. I've recently noticed
that a recurring display occurs:

HHC02324I PSW=078D2000000383EC INST=BA661000 CS 6,6,0(1)
compare_and_swap HHC02326I

V:00FE3E30:R:00000000007E3E30:K:06=009BCD10 809BCF98 ...
[...]

HHC00801I Processor CP00: Protection exception code 0004 ilc 4

[...]

Am I doing something wrong to cause this? It looks like these
messages are going to the log file and there's a lot of these!

They *appear* to be legitimate errors, as in whatever you're running in/on your
guest is not doing something correctly (i.e. something is malfunctioning, i.e.
some piece of software you're running is buggy).

According to the PSW, the program is running in Problem State with PSW Key 8
(the "8D" in your PSW), but the storage the 'CS' (Compare and Swap) instruction
is trying to access is Key 0 (the '0' in "K:06"), which by my calculations would
indeed cause a bona fide Protection Exception Program Interrupt.

<shrug>

Check your code. I suspect it's buggy.

--
"Fish" (David B. Trout)
Software Development Laboratories

mail: fish@...

?

?

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Fish Fish
Sent: 26 October 2022 05:35
To: [email protected]
Subject: Re: [h390-vm] Do I have a looping issue?

René Ferland wrote:

Jim Snellen wrote:

Am I doing something wrong to cause this?

You are not doing anything wrong Jim.

I disagree. (Well, maybe not HIM, but *something* *somewhere* in one of his
guests is definitely doing something wrong!)

IIRC, these messages come from the tailoring of the OS by Hercules, as
specified by the OSTAILOR statement in the configuration file. Check
the documentation of Hercules to set this parameter to an appropriate
value for you.

OSTAILOR is *not* going to help in this situation. The defined default OSTAILOR
values for each supported flavor of operating system will *never* mask a
Protection Exception. A Protection Exception is an indication of a bona fide
programming error somewhere.

Check your code. It's buggy.

--
"Fish" (David B. Trout)
Software Development Laboratories

mail: fish@...

Hello Harold,

As the originator of this thread, my goal was two fold. First, to
provide a file level backup (and possibly restore) solution. Second,
it was to get back into VM again. I stopped using VM, unfortunately
in 1992 or so (other than as a G user).

It is why I wrote the subject as "Would anyone like ..." I thought
maybe there was already an existing VM/CE solution. From what I'm
reading there isn't a VM/CE file level backup solution. I even
remember reading one person saying he'd like to use it on a live
VM/ESA real iron system.

I look forward to bringing it back to life for my own resurrection in
the VM world. At the time people liked the approach to ask me to
present at Share and IBM wanted to buy the rights from OCF to it.

I hope this reply answers some of your questions. As for using
Windows to backup our system, sure but its like doing a DDR backup
and restore. You lose all of the system changes since the last DDR
or Windows backup. It also wouldn't help the VM/ESA guy or help me
come back to VM.

Bertram Moshier



On Tue, Oct 25, 2022, 07:41 Harold Grovesteen <h.grovsteen@...>
wrote:

I have watched this thread and continue to come away with "what is
the
objective of this discussion?" Is it about backing up your VM DASD
or
is it about resurrecting some past capability? I realize it could
be
both.

But, no one has mentioned that in the Hercules world, backing up
ones
DASD can be done quite easily. Place all of your DASD host files
in
the same directory. Shut down VM. Compress and zip up all of the
DASD
images into an archive file.

Recovery is the reverse, but attach your unzipped DASD volume(s)
from
which you want to recover files or minidisks to those already gened
extra drives in VM and move what needs moving. The Hercules
configuration file makes this connection.

Be careful to preserve shadow files if you are using them.

This may not work as desired so feel free to shoot it down. Just
an
approach I have not seen discussed.

Recovery is ad hoc in most cases. So some augmentation with some
VM
data when the backup is made might help. But this boils down to
level
of effort. Let the host do the heavy lifting where it can.

Some folks like to stay within the "VM walls". That is perfectly
OK,
but we are living in a different world with Hercules and can
approach
problems with Hercules and its host being part of the solution.

Harold Grovesteen

On Sun, 2022-10-23 at 08:54 -0500, Bertram Moshier wrote:

+Hi,


I'm wondering if a VM Backup program would be useful for people

using

VM/CE. I can see both reasons being yes and no. Thus my

question

about a VM Backup program for VM/CE?

Thanks.

This a family oriented group.

Please don't use four letters words like "OSI" (especially since OSI
lost the war to TCP/IP around same time UUCP did!)

+Hi,


I'm wondering if a VM Backup program would be useful for people using
VM/CE. I can see both reasons being yes and no. Thus my question
about a VM Backup program for VM/CE?

Thanks.

Bertram Moshier wrote:

[...]

As it has been awhile and I'm new to VM/CE, one of the things
I need to know is how much data can I get on a 6250 reel of tape?

With Hercules, this is user configurable and controlled by the optional "MAXSIZE=" and "EOTMARGIN=" tape drive device parameters:

*

If not specified, then basically there is no limit as far as Hercules is concerned. It will continue writing to your emulated tape drive device file until your hard drive fills up (or your job finishes, whichever comes first).

If you're just trying to refresh your memory regarding how much data one could typically fit on a REAL 6250 bpi reel of tape back in the day, the following are the values as documented by my HercGUI:

2048MB (typical 1370' 3490E cartridge)
170MB (typical 2400' 9-track @ 6250 BPI)

2048KB (~20 inches of 3490E cartridge)
128KB (~20 inches of 9-track @ 6250 BPI)

I no longer recall where I got those values from but I'm guessing they're reasonably accurate.

What other backup devices does VM/CE support beside a 6250 drive?

VM/CE? I have no idea.

But Hercules supports emulation of 3410, 3420, 3422, 3430, 3480, 3490, 3590, 9347 and 8809 model tape drives.

Emulated tape drives can be defined as AWS or HET files, or OMA or TDF files, or even honest to goodness actual REAL SCSI attached tape drives. That is to say, if you have a REAL (as in an actual physical hardware device) tape drive physically connected to your system as a SCSI device, Hercules can use it. Otherwise the Hercules tape drive is emulated in the same way disk drives and card readers, etc, are emulated: by simply reading or writing to a disk file on your host [Windows/Linux/etc] filesystem.

Given there aren't real tapes, how does changing tapes work for Herc
and VM/CE?

As explained above, the MAXSIZE= and EOTMARGIN= emulated tape drive device parameters control when the end-of-tape reflector is reached. As far as how the guest operating system deals with such things, I'm sure it varies from one operating system to the next. <shrug>

Hope that helps!