sms and non-sms data sets?

[Kishor Sonawane]

Hi,

What are SMS MANAGED DATA SETS AND NON SMS MANAGED DATA SETS? As a programmer does that make any difference in coding? Or it's a system-level concept?

[zprogrammer]

To Start with:

Read this http://publibz.boulder.ibm.com/cgi-bin/ ... 1201115546

[Anuj Dhawan]

In very simple words - if a dataset has a valid STORCLAS it is SMS managed or usually if the STORCLAS is not null the dataset is SMS managed.

This is controlled by the SMS ACS routines, and this can allow some selected users to create datasets outside of SMS, where in most cases all other users are forced int SMS managed datasets.

This is from a distant memory and an important one that - SMS does not support uncataloging of data sets. So, when getting rid of a data set that is no longer being used do the following:

1. Use DELETE not UNCATLG .
2. DO NOT USE DEL NOSCR -- This is the same as uncataloging the dataset.

[Robert Sample]

System-managed data sets (SMS MANAGED) MUST be cataloged as pointed out. From a programmer's viewpoint, there is no difference between data sets that are SMS managed and non-SMS managed. Most programmers, in fact, cannot create non-SMS managed data sets as these are usually system data sets that follow specific site requirements. SMS managed data sets are placed in storage pools and the programmer does not get to choose which disk volume the data set is placed on; non-SMS managed data sets require that the programmer specify the disk volume upon which the data set will reside.

[Kishor Sonawane]

Thanks. Does someone of you have some more references on this, which is put in simple format rather than as IBM Redbook?

[byelen]

Hi Kishor,

You'll really have to check what policies are in effect for the system you're working on. SMS can be based on high level qualifier, userid, and a host of other parameters. It really depends on what a specific shop is trying to do. In our case, we're using it to determine where datasets should be stored. If the HLQ's indicates that it's payroll (as an example), it will be stored with other payroll datasets. HLQ's that match a TSO userid will go to a different volume pool (and so on). Essentially, we set up the policies, and then just ignore them. SMS does what it will, and if we find it's not doing what we need it to do, we alter the policy accordingly.

- Bruce

[Robert Sample]

I'm not clear what you want more references on -- writing SMS rules? how SMS works? what your site rules are? defining storage pools?

Be aware that SMS is a large, complex topic and while some simplifications are possible, there is a lot in the manuals and Redbooks that you MUST learn in order to understand and use SMS properly (at least, from a systems standpoint -- as pointed out, the application programmer rarely has any need to know more than the fact that the site has SMS installed, and perhaps which storage pools the application data sets go into).

[Kishor Sonawane]

Thanks Bruce.

Hi Robert -

I'm not clear what you want more references on -- writing SMS rules? how SMS works? what your site rules are? defining storage pools?

I'm trying to learn the first two parts of your response: How to writie SMS rules and how SMS works?

[Robert Sample]

You can learn some of how SMS works, but if you want all the details you are going to be disappointed -- only someone working for IBM in their storage management development group would have those details. There is a bookshelf called DFSMS that IBM maintains -- if you don't have the appropriate web site for your release of z/OS bookmarked yet, I recommend you find it (Google is your friend) and bookmark it. In that bookshelf is a manual entitled DFSMS Implementing System-Managed Storage -- if you find and read this manual, you will learn what IBM wants you to know about how SMS works as well as how to write ACS routines (the code SMS uses to manage data sets). The manual also goes into ISMF, which is the TSO software that allows a site to define and manage storage groups. ISMF and ACS routines interact so you do need to do a LOT of learning before attempting to change anything already in place.

[Kishor Sonawane]

Thanks All!