Maximum Space allocation for a PS dataset in cylinders

Sivagurunathan Jagadeesan · New User Joined: 06 Mar 2007 Posts: 32 Location: India

Hi,

I have to run a job in production; the volume of record which will be extracted is expected to be high (in the order of millions). I don?t want the job to abend due to lack of space. Can someone suggest me what can be the maximum space allocation for a PS dataset in terms of cylinders?

Thanks,
Siva

murmohk1 · Posted: Thu May 03, 2007 2:33 pm

Jagadeesan

expat · Posted: Thu May 03, 2007 2:41 pm

The number of cylinders you can allocate depends mainly on the number of cylinders you have available within ONE SMS storage group, or the number of cylinders available on nom SMS devices.

Consider also the device geometry, are you using 3390-3, 3390-9, 3390-27, 3390-54.

As Murali has said, if you want to be sure then use a tape in the first instance, but also investigate the default number of tapes set by the systems programmers.

You can override the default by using the VOL parameter, usually 99 works pretty good.

dick scherrer · Posted: Thu May 03, 2007 8:43 pm

Hello,

How many records and how many bytes for each?

Once you know the above and what model of dasd you have available for use, the amount of space can be calculated. Once you know the amount of space needed, your storage management people can tell you if there is enough space for your run.

One important thing to consider is whether this file is to be kept for future use or if it is a transient file (used a short time and diacarded when the process(es) using it are succesfully completed (i.e. month end).