KSDS sharing between two systems

Grant Goodale · Posted: Tue Jan 14, 2014 8:07 am

I want to define a KSDS that will be shared between two or more LPARs, provided that it resides in shared DASD, of course. I am currently using SHR(3 3). Is this possible if the two systems do not share catalogs? I cannot see any way to define it on the second system using IDCAMS.

I have done a search and I did not notice anything that addresses this issue but I might have missed something.

TIA

sureshpathi10 · Posted: Wed Jan 15, 2014 10:26 am

Hi,

I'm guessing that, you want to create a KSDS that can be accessible in multiple LPARs.

Here are my thoughts:
When you DEFINE a KSDS it will be cataloged in that LPAR. Only the VOLUME is shared across the systems not the catalogs. So, You need to catalog the same KSDS file in the second LPAR by specifying the VOL Serial.

Note: I've faced this problem with the normal PDS and fixed like above mentioned. I'm not sure how this will work with VSAM.

Grant Goodale · Posted: Wed Jan 15, 2014 7:02 pm

Suresh -

I have tried to do that DEFINE with the VOL parameter but IDCAMS complains that there are no space specifications. I know that I can do it with a non-VSAM. It looks like a shared catalog is the only way of getting access.

Thanks.

enrico-sorichetti · Posted: Wed Jan 15, 2014 7:20 pm

I strongly suggest to read

www.redbooks.ibm.com/redbooks/pdfs/sg246105.pdf

Grant Goodale · Posted: Wed Jan 15, 2014 10:33 pm

Enrico -

Interesting document. I think that I will just use a shared user catalog. It seems like the simplest solution.

Thanks

enrico-sorichetti · Posted: Wed Jan 15, 2014 11:05 pm

do You have already a plan to provide INTEGRITY

Grant Goodale · Posted: Wed Jan 15, 2014 11:27 pm

Yes - cross system ENQs

Bill O'Boyle · Posted: Thu Jan 16, 2014 1:41 am

Grant,

Have you researched the MVS Coupling Facility and MVS Logger?

Grant Goodale · Posted: Thu Jan 16, 2014 6:39 am

Personally, no but I believe that one of my co-workers is conversant in these items. I will check them out myself.

Thanks for the suggestion.

PeterHolland · Posted: Thu Jan 16, 2014 11:00 am

You will find some interesting info here (pdf alert) :

www.google.nl/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&ved=0CDcQFjAB&url=https%3A%2F%2Fshare.confex.com%2Fshare%2F116%2Fwebprogram%2FHandout%2FSession8978%2FSHARE%2520Best%2520Practices%2520for%2520ICF%2520Catalog%2520and%2520VSAM%2520Anaheim%2520S8978.pdf&ei=j23XUs-IKMjI0wWx24CgCQ&usg=AFQjCNHgOPD-XZDl0wr1WSiAZ3BSVzKF5Q&bvm=bv.59568121,d.bGQ

Grant Goodale · Posted: Sun Jan 19, 2014 6:13 am

Peter -

Interesting reading. Thanks

- Grant

Pete Wilson · Posted: Wed Feb 26, 2014 10:25 pm

This is a messy and ill advised route to go down, trust me. If it can't be in a proper shared catalog then don't do it, unless perhaps it is a completely static unchanging file.

For one, the catalog stat's are always going to be wrong once any updates are done because the 'other side' wouldn't be aware of it. So any process opening the file is going to be invoking implicit verifies every time I suspect which could be a large overhead. Not sure if the Catalog Address Space (CAS) is going to be too happy either. Also may require special treatment in GRS.

You can try doing a DEFINE with the VOLUMES and RECATALOG parameters, but not sure it will work. It uses the VVDS information to build the catalog information and it knows what catalog the file was originally defined to as that's stored in the VVR record. You may have to define a usercatalog on the 'other' system with the same name to do the RECATALOG, but that may not be feasible if the ALIAS points somewhere else.

Grant Goodale · Posted: Thu Feb 27, 2014 1:08 am

Pete -

I have opted to go the shared catalog route. Anything else looks like a horror story.