I am not a LUW person, other than I use a windows machine for simple things, so 
I am curious how external storage is allocated and controlled in that 
environment.  I think we have all heard the complaints about the short-comings 
of MVS in this area, but what would be a realistic solution?

I would imagine the people at IBM have spent a little time on this, and if it 
was easy would have started transitioning us from ECKD to 'the new way' a long 
time ago.  The idea of a 'run-away' program is what is the hang-up.

Chris Blaicher
Principal Software Engineer, Software Development
Syncsort Incorporated
50 Tice Boulevard, Woodcliff Lake, NJ 07677
P: 201-930-8260  |  M: 512-627-3803
E: cblaic...@syncsort.com

-----Original Message-----
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf 
Of Farley, Peter x23353
Sent: Monday, June 10, 2013 10:38 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Storage paradigm [was: RE: Data volumes]

<Rant>
Like a few others on this list, I have often gritted my teeth at the necessity 
to estimate disk storage quantities that vary widely over time in a fixed 
manner (i.e., SPACE in JCL) when the true need is just to match output volume 
to input volume each day.

Why is it that IBM (and organizations that use their mainframe systems) so 
vigorously resist a conversion off of the ECKD "standard"?  (Yes, I know it's 
all about "conversion cost", but in the larger picture that is a red herring.)  
Not that I'm likely to see such a transition in my lifetime, but in this 
dawning time of soi-disant "big data", perhaps it is past time to change the 
storage paradigm entirely, not from ECKD to FBA but to transition instead to 
something like the Multics model where every object in the system (whether in 
memory or on external storage, whether data or program) has an address, and all 
addresses are unique.  Let the storage subsystem decide how to optimally 
position and aggregate the various parts of objects, and how to organize them 
for best performance.  Such decisions should not require human guesstimate 
input to be optimal, or nearly so.  Characteristics of application access are 
far more critical specifications than mere size.  The ability to specify just 
the desired application access characteristics (random, sequential, growing, 
shrinking, response-time-critical, etc.) should be necessary and sufficient.

EAV or not EAV, guaranteed space or not, candidate volumes, striped or not 
striped, compressed or not compressed - all of that baggage is clearly 
non-optimal for getting the job done in a timely manner.  Why should allocating 
a simple sequential file require a team of "Storage Administration" experts to 
accomplish effectively?
</Rant>

Peter

-----Original Message-----
From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf 
Of Ed Jaffe
Sent: Sunday, June 09, 2013 10:47 AM
To: IBM-MAIN@LISTSERV.UA.EDU
Subject: Re: Data volumes

On 6/9/2013 7:12 AM, Scott Ford wrote:
> We need bigger dasd ...ouch

The largest 3390 volumes in our tiny shop hold 3,940,020 tracks or 262,668 
cylinders. That is the maximum size supported by the back-level DASD we are 
running. Newer DASD hardware can support volumes up to 1TB in size. I assume 
nearly all zEC12 and z196 customers are capable of exploiting these large 
sizes. But, do they?

I spent three years dealing with, and eventually helping IBM to solve (via 
OA40210 - HIPER, DATALOSS), a serious EAV bug that should have been seen in 
most every shop in the world that uses the DFSMSdss CONSOLIDATE function (with 
or without DEFRAG). The experience was a real eye-opener for me and I concluded 
that almost nobody is using EAV!

Why not? Personally, I would find it embarrassing if the Corsair thumb drive in 
my pocket held more data than our largest mainframe volumes.
But, that's just me...
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