Using a VSAM linear data set

Using a VSAM linear data set for output trace data provides better performance than using a sequential data set.

Perform the following steps:

1. Define a VSAM Linear data set.

   //DEFINE EXEC PGM=IDCAMS               
   //SYSPRINT DD SYSOUT=*                 
   //SYSIN    DD *                         
    DELETE +                                     
        (hlq.CTRACE.LINEAR)     +            
      CLUSTER                             
    DEFINE CLUSTER( +                        
    NAME(hlq.CTRACE.LINEAR)     +           
    LINEAR                      +           
    MEGABYTES(10)               +           
    VOLUME(CPDLB0)              +           
    CONTROLINTERVALSIZE(32768)  +           
    )                           +          
    DATA(                       +          
    NAME(hlq.CTRACE.DATA)       +           
     )                                      
   LISTCAT ENT(hlq.CTRACE.LINEAR) ALL 

2. Update the CTRACE writer procedure:

   //IEFPROC  EXEC PGM=ITTTRCWR                         
   //TRCOUT01 DD DSNAME=hlq.CTRACE.LINEAR,DISP=SHR   
   //SYSPRINT DD SYSOUT=*                        

3. Issue the COPYTRC command. The VSAM data set must be copied with COPYTRC to a sequential data set before being sent to IBM® Service.