IBM Mainframe Forum Index
 
Log In
 
IBM Mainframe Forum Index Mainframe: Search IBM Mainframe Forum: FAQ Register
 

Model of a GDG


IBM Mainframe Forums -> JCL & VSAM
Post new topic   Reply to topic
View previous topic :: View next topic  
Author Message
saurabh39
Warnings : 1

Active User


Joined: 11 Apr 2008
Posts: 144
Location: Jamshedpur

PostPosted: Thu Jun 07, 2012 9:01 pm
Reply with quote

Hi All,

There was a NDM process in our shop, which used to work correctly and create a file(GDG Version) of length 320 Bytes and FB.

But now, the NDM process is creating a VB file(GDG Version) with LRECL 23036. We wanted to if GDG Model definition has changed or not, so was wondering if there is a way to find the GDG model definition.
Back to top
View user's profile Send private message
Naish

New User


Joined: 07 Dec 2006
Posts: 82
Location: UK

PostPosted: Thu Jun 07, 2012 9:14 pm
Reply with quote

See if this helps.

ibmmainframes.com/viewtopic.php?t=33132&highlight=model+gdg
Back to top
View user's profile Send private message
Robert Sample

Global Moderator


Joined: 06 Jun 2008
Posts: 8697
Location: Dubuque, Iowa, USA

PostPosted: Thu Jun 07, 2012 9:20 pm
Reply with quote

The GDG model is applied when the generation is created, so you need to check (a) the JCL buildling the dataset, or (2) the SMS rules -- a model is NOT tied to a GDG base, so different generations of a GDG can have completely different DCB data. Hence asking
Quote:
We wanted to if GDG Model definition has changed or not, so was wondering if there is a way to find the GDG model definition.
is making wrong assumptions since the GDG model definition doesn't apply to a GDG except at the one point in time when the generation is being created.
Back to top
View user's profile Send private message
expat

Global Moderator


Joined: 14 Mar 2007
Posts: 8797
Location: Welsh Wales

PostPosted: Fri Jun 08, 2012 1:35 pm
Reply with quote

If the ACS routines are correctly defined then there is absolutely no need for a model or pattern DSCB for either SMS managed or non SMS GDS
Back to top
View user's profile Send private message
Pete Wilson

Active Member


Joined: 31 Dec 2009
Posts: 582
Location: London

PostPosted: Fri Jun 08, 2012 3:13 pm
Reply with quote

Sounds like some change in parameters used in the NDM process or possibly in the source data attributes which NDM would base it's allocation on.
Back to top
View user's profile Send private message
Anuj Dhawan

Superior Member


Joined: 22 Apr 2006
Posts: 6250
Location: Mumbai, India

PostPosted: Fri Jun 08, 2012 4:13 pm
Reply with quote

saurabh39 wrote:
But now, the NDM process is creating a VB file(GDG Version) with LRECL 23036. We wanted to if GDG Model definition has changed or not, so was wondering if there is a way to find the GDG model definition.
First question should be, is something changed now?

And DSCB well, long back - when I was not born - a DSCB is a single record in a VTOC . There are several types of DSCBs, referred to as Format n DSCBs. DSCB are often 0 track data sets. Before SMS, the model DSCB for a generation data group was a data set that was not cataloged and that had a data set name that matches the generation data group name.

The data set had to be allocated on the same volume as the catalog where the generation data group was allocated. Long back, in the original OS/360 it was not acceptable to have two catalog entries of two different types with the same name, which was why the GDG model was allocated on the same volume as the catalog, but was not itself cataloged (TRK 0). Again, with OS/360, if there was no model DSCB, the system would not allocate the data set unless the JCL specified a model DSCB data set name. But it's 2012 and I've not worked at a single site using less than z/OS 1.11 since some while now - this is SMS-managed era. And wtih SMS, the DSCB is obsolete -- so problem lies somewhere else, possibly with NDM (Direct:Connect).
Back to top
View user's profile Send private message
View previous topic :: :: View next topic  
Post new topic   Reply to topic View Bookmarks
All times are GMT + 6 Hours
Forum Index -> JCL & VSAM

 


Similar Topics
Topic Forum Replies
No new posts Panel variable model line TSO/ISPF 3
No new posts Dynamically switching terminal model TSO/ISPF 9
No new posts Help needed on GDG Base Model and Gen... JCL & VSAM 18
No new posts Model 204 DBMS. DB2 6
No new posts SYSPLEX Named counter and TSQ model All Other Mainframe Topics 1
Search our Forums:

Back to Top