Re: UNIT=SEP still alive (?)

2013-08-31 Thread Ron Hawkins
I forget when it was, but quite some time ago, perhaps pre-SMS, allocation
started massaging the Eligible Device list so that unit addresses already
allocated to a DD in a step were moved to the bottom of the EDL.

The reason for this was to prevent the behavior I think you are describing
below - all new datasets allocated to the same volume because it was at the
top of the EDL. This is why you'll see all SORTWKnn datasets allocated to
different volumes if the number of eligible devices is greater than the
number of new datasets.

I think this change to allocation may have made UNIT=SEP redundant.

Ron

> -Original Message-
> From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU]
> On Behalf Of efinnell15
> Sent: Friday, August 30, 2013 11:39 AM
> To: IBM-MAIN@LISTSERV.UA.EDU
> Subject: Re: [IBM-MAIN] UNIT=SEP still alive (?)
> 
> We had one in early XA ESP where techy changed a few jobs and had
> UNIT=3800 for SORTWKs  and it tried to honor it. Can you say wreck?
> 
> 
> 
> In a message dated 08/30/13 13:23:33 Central Daylight Time,
> gerh...@valley.net writes:
> He reported that a "CoBOL" programmer submitted a sort job with all sort
> work files on the same 2321 data cell drive!
> 
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Re: UNIT=SEP still alive (?)

2013-08-31 Thread Paul Gilmartin
On Fri, 30 Aug 2013 21:22:02 -0400, Robert A. Rosenberg wrote:
>
>I know for multi-volume datasets UNIT=(TAPE,2) handled the mount of
>volume3 while volume1 rewound and unloaded. I do not remember if you
>could allocate 2 units and have concatenated input volumes alternate
>between them. AVR might have helped since it say "Find the device
>with the Tape Volume and allocate the DD to it" but I do not think it
>would handle the case where you want to reuse a drive where the tape
>has unloaded - It was for allocation at step start.
> 
I know from experience that AVR is ineffective once the OS has issued
the mount message to the console.  If I've been tardy mounting a tape,
I must read the console message; dismount the tape; and move it to
the drive requested.  (It may have been for scratch requests; again,
there's no response to tell allocation, "The scratch tape you need is
already mounted on drive nnn; use it!")  PITA.

-- gil

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