What is allocation maximum for the Daily logfile and why does the primary allocation might not match the value specified.

Products

• SMR

Issue/Introduction

 Sometimes the daily logfile needs to be increased, since it no longer can cover a whole day due to increased activities.
The SMR Getting started guide does not mention a maximum value for the PRIMRY or the SECDRY allocation parameter of the PL34OPTN member.
In addition once the daily logfile is allocated you may wonder why the specified allocation is not taken into account.

 

 

Resolution

The maximum value of the PRIMRY or SECDRY allocation parameter is 32767. Depending on the SPACE parameter this can be either Cylinder or Tracks.

The primary allocation is given to z/OS? dynamic allocation. z/OS does not guarantee that the primary allocation is given in one chunk. Therefore the primary allocation given by z/OS depends on the contiguous space available.