TSO Region Size

Martin Wickenden · New User Joined: 24 Apr 2018 Posts: 15 Location: USA

I am trying to increase my TSO region size (currently 4096) so that I can work with JAVA and OMVS (installing a product that requires answers to prompts, so I can't use BPXBATCH). I get "LOGON FAILED" message when I attempt a larger region size, no other information given. I am on page 77 of TSO Customization manual stating TSO/E search order for region size and IKJEFLD exit described in chapter 8. I have already increased my RACF MAXREGION. It appears that I must code the logon pre-prompt exit IKJEFLD to increase my region? Does any one have experience with this, there must be an easier way. Thanks in advance, Martin Wickenden

Robert Sample · Posted: Wed Aug 15, 2018 11:44 pm

Is the site JES2 or JES3? If JES2, is TSUCLASS set in the JES2 initialization parameters?

Is there a chance that IEFUSI / IEALIMIT are controlling the region size?

Also, is there a REGION parameter set for the EXEC statement in the logon proc?

Another possibility would be that your RACF user id (assuming your site uses RACF) could have an ACCOUNT with maximum region size.

Yes, the logon pre-prompt exit is searched first but I don't think I've heard of any sites using it; there are too many other (easier) ways to control TSO region size.

Martin Wickenden · New User Joined: 24 Apr 2018 Posts: 15 Location: USA

Ok, I have JES2 and RACF, the TSUCLASS is set to 16M, no REGION parm in LOGON proc. I have SIZE of 8192 and MAXSIZE of 16384 in RACF. Thanks.

Robert Sample · Posted: Thu Aug 16, 2018 12:17 am

I don't recall if 16M is enough for Java in TSO -- you might need to check the BPXPRMxx size parameters, too, if you run into Java issues.

vasanthz · Posted: Thu Aug 16, 2018 1:56 am

Specify a large value like 64000 on your TSO logon screen. At the same time you would need the high value allowed on RACF TSO segment.

You have to specify a number bigger than 32768 to increase your actual region size.

Here is why - www.askthezoslady.com/tso-region-size-really-means/

What does specifying an 8 Meg (8192K) TSO Logon Region Size mean?

It does Not mean you get an 8 Meg region size. Nice guess, and a funny idea, but no. For that matter, REGION=8M in JCL doesn't get you 8 Meg there, either. Hasn't done so for decades (despite what you may have heard or read elsewhere. If you have trouble believing this, feel free to skip down a few paragraphs, where you can find a link to some IBM doc on the matter.)

No, your region size defaults to at least 32 Meg, regardless of what you specify.

Despite the omnipresent threat that the people who set up your own particular z/OS system might have changed the IBM defaults there, or (who knows) might even have vindictively limited your own personal userid — For this discussion, we're assuming you're using a more or less intact z/OS system with the IBM defaults in effect.

So, you ask, What happens when you specify Size 8192 at Logon?

Size ===> 8192

When specifying Size=8192, you will be allowed to use up to 32 Meg of 31-bit addressable memory. This is the ordinary kind of memory that most programs use. You will get this for any value you enter for Size until you get up to asking for something greater than 32 Meg. Above 32 Meg, the Size will be interpreted differently.

If you enter a number greater than 32 Meg (Size ===> 32768), that will be interpreted in the way you would expect – as the region size for ordinary 31-bit memory.

Willy Jensen · Posted: Thu Aug 16, 2018 2:48 am

Getting to your TSO logon screen:
Exit from ISPF till you get the TSO READY prompt.
Issue command LOGON your-user-id

Martin Wickenden · New User Joined: 24 Apr 2018 Posts: 15 Location: USA

Thanks very much for all your help. I was able to increase region size to 64000 by increasing in RACF TSO segment and specifying on the LOGON screen. This forum is very helpful, best wishes, Martin Wickenden

vasanthz · Posted: Fri Aug 17, 2018 1:32 am

Glad you got it figured out :-)

Whenever a topic starter comes back and says how the problem was resolved,
It definitely brings closure to the people posting on the thread.