Running conditional tracing

Conditional tracing allows users to turn off some of the problem determination aid (PDA) tracing and CAPACITYMODE tracing that DFSMShsm normally performs.

If conditional tracing is OFF, performance improves. If conditional tracing is ON, serviceability improves. Users must be aware, however, that if any tracing is off, then data capture on the first failure may be compromised, and may require a problem recreation.

The default for tracing is to trace everything.

Three tracing functions can be turned off with the following PATCH commands:

 PATCH .MCVT.+558 BITS(0.......) /* OFF=Do not trace CPOOL calls   */ 
                                 /* (GETCELL or FREECELL)          */


PATCH .MCVT.+558 BITS(.0......)  /* OFF=Do not trace entries with         */ 
                                 /* CONDitional or CAPACITYMODE specified */


PATCH .MCVT.+558 BITS(..0.....)  /* OFF=Do not trace entries of        */ 
                                 /* REJECTION during volume selection  */