how much space does it occupy?



JES, JES2, JCL utilities, IDCAMS, Compile & Run JCLs, PROCs etc...

how much space does it occupy?

Postby ranga_subham » Mon Oct 10, 2011 4:18 pm

Hi, One of our job is daily abending with SB37. Below given are parameters coded on output dataset:

//DSNOUT   DD DSN=OUTPUT.DATASET,       
//           DISP=(NEW,CATLG,DELETE),       
//           UNIT=TEMPDA,
//           SPACE=(10796,(600,300),RLSE),   
//           DCB=(RECFM=FB,LRECL=80,DSORG=PS,
//             BLKSIZE=3120)                 


We modified the SPACE to below value to overcome space abend.

//           SPACE=(10796,(1500,1000),RLSE), 


Can you please help me to understand what could be the problem with this kind of coding? And, I would like to know how much space this one turns out to be? What is the better way of coding it?

Please help.

Thanks.
ranga_subham
 
Posts: 279
Joined: Fri Jul 18, 2008 7:46 pm
Has thanked: 0 time
Been thanked: 1 time

Re: how much space does it occupy?

 

Re: how much space does it occupy?

Postby Robert Sample » Mon Oct 10, 2011 4:52 pm

First, you need to understand that you are completely on the wrong path. In order to know how much space you need to allocate, you MUST know the number of records to be written to that file. If you don't know, then a guess is fine -- but the block size, record length, and number of records is all you need to figure out the required space.

Second, your posted JCL is garbage. If you look at your site's copy of the MVS JCL Reference manual, or even look at the IBM web site to find it, you will find that SPACE=(10796,(600,300),RLSE), is allocating primary space of 600 blocks at 10796 bytes each since you are NOT using AVGREC. Since your record length is 80 and you are using fixed length records, the block size is supposed to be an even multiple of 80. 10796 is not. I suspect the only reason you did not get a JCL error is because you specified BLKSIZE=3120, which IS an even multiple of 80.

Third, the SB37 means either (a) your data set hit 16 extents and needed more -- in which case your allocation needs to be at least 5100 for primary -- or (b) your data set did not hit 16 extents but the disk volume ran out of space, in which case you either need to allocate on a different volume or provide more volumes for the data set.

Fourth, allocating in blocks in wasteful -- use cylinders to reduce system overhead to a minimum, espeically since you apparently have a good bit of data in this data set.
Robert Sample
Global moderator
 
Posts: 3367
Joined: Sat Dec 19, 2009 8:32 pm
Location: East Dubuque, Illinois
Has thanked: 1 time
Been thanked: 222 times

Re: how much space does it occupy?

Postby steve-myers » Mon Oct 10, 2011 5:36 pm

Mr. Sample's discussion is excellent. His argument to allocate space in cylinders is 100% correct, though translating your requirement to cylinders is not always easy. However, you can make z/OS do the translation for you! Specify ROUND the JCL SPACE parameter to ndirect z/OS to do the translation. This is tricky because it's positional, and I always (yes, after more than 40 years!) have to use the JCL manual to specify it.

More in point, you can easily get the current space for a dataset by using ISPF option 3.2.
steve-myers
Global moderator
 
Posts: 1885
Joined: Thu Jun 03, 2010 6:21 pm
Has thanked: 4 times
Been thanked: 197 times

Re: how much space does it occupy?

Postby ranga_subham » Mon Oct 10, 2011 7:09 pm

Hi Robert & Steve,

Thanks a lot for your inputs...........the problem is this dataset gets deleted because it got below disposition.

DISP=(SHR,DELETE,KEEP)


So, I am unable to find the exact details. I am planning to change block size from BLKSIZE=3120 to BLKSIZE=0 and introduce AVGREC=K as suggested by Robert. I wonder why this space calculation is always a puzzle and not easy to digest !! How the problem had been resolved with increased space parameters?

Thanks.
ranga_subham
 
Posts: 279
Joined: Fri Jul 18, 2008 7:46 pm
Has thanked: 0 time
Been thanked: 1 time

Re: how much space does it occupy?

Postby Akatsukami » Mon Oct 10, 2011 10:18 pm

ranga_subham wrote:Hi Robert & Steve,

Thanks a lot for your inputs...........the problem is this dataset gets deleted because it got below disposition.

DISP=(SHR,DELETE,KEEP)

And yet, in your first post, you allege that it has a disposition of (NEW,CATLG,DELETE). What is the cause of this discrepancy?
"You have sat too long for any good you have been doing lately ... Depart, I say; and let us have done with you. In the name of God, go!" -- what I say to a junior programmer at least once a day
User avatar
Akatsukami
Global moderator
 
Posts: 1053
Joined: Sat Oct 16, 2010 2:31 am
Location: Bloomington, IL
Has thanked: 6 times
Been thanked: 51 times

Re: how much space does it occupy?

Postby ranga_subham » Tue Oct 18, 2011 4:03 pm

Looks like you are new to mainframe programming........You can't have DISP=(SHR,DELETE,KEEP) on a new dataset getting created :x :shock:

Thanks.
ranga_subham
 
Posts: 279
Joined: Fri Jul 18, 2008 7:46 pm
Has thanked: 0 time
Been thanked: 1 time

Re: how much space does it occupy?

Postby Akatsukami » Tue Oct 18, 2011 6:17 pm

ranga_subham wrote:Looks like you are new to mainframe programming........You can't have DISP=(SHR,DELETE,KEEP) on a new dataset getting created :x :shock:

Ah, so you've started talking about something that you concealed from us in your initial post! :P
"You have sat too long for any good you have been doing lately ... Depart, I say; and let us have done with you. In the name of God, go!" -- what I say to a junior programmer at least once a day
User avatar
Akatsukami
Global moderator
 
Posts: 1053
Joined: Sat Oct 16, 2010 2:31 am
Location: Bloomington, IL
Has thanked: 6 times
Been thanked: 51 times

Re: how much space does it occupy?

Postby dick scherrer » Tue Oct 18, 2011 10:37 pm

Hello,

Looks like you are new to mainframe programming........You can't have DISP=(SHR,DELETE,KEEP) on a new dataset getting created
You (r_s) were the one who posted this. Why do you now say this "looks like someone new to mainframe"?

Everyone else participating in this topic is a "senior".

Possibly, ive gotten lost here .
Hope this helps,
d.sch.
User avatar
dick scherrer
Global moderator
 
Posts: 6304
Joined: Sat Jun 09, 2007 8:58 am
Has thanked: 3 times
Been thanked: 91 times


Return to JCL

 


  • Related topics
    Replies
    Views
    Last post