What is AFF=ddname (this comes in the UNIT parameter)

murali922 · Active User Joined: 25 Jul 2005 Posts: 92 Location: India

Hi,

Could anyone let me know what is the use of coding this in a JCL :

AFF=ddname (this comes in the UNIT parameter)..

ksreddy1976 · New User Joined: 28 Jun 2005 Posts: 8

UNIT=AFF when Requesting Extended Data Sets in a JES3 System

In a multiple-step job in a JES3 system, if a data set is extended in an early job step to additional volumes, MVS allocates the additional devices needed. JES3 is unaware of the additional devices. If a later step requests the data set, code UNIT=AFF=ddname so that the system allocates the original and additional devices for the data set.

murali922 · Active User Joined: 25 Jul 2005 Posts: 92 Location: India

Does this mean that :

step 1 : I have a dataset with name as DS1, with space=(cyl,(1,5)). And I do some processing to make this dataset full.

step 2 : I am trying to use the dataset. And this time I would code UNIT = AFF = DS1 or <the name of the new dataset>

If I use AFF= it would use the same volume used by DS1 or it would create the same amount of space but in a different memory location ??