In addition to the automatic dumps previously described, you can also optionally specify whether VSAM Record Management dynamic dumping is to occur for specific events identified by a combination of a return code, error (reason) code, problem determination function (PDF or FUNC) code, and component code returned in the request parameter list (RPL) feedback area. (See Return codes from the record-management (request) macros.)

You can request a user directed dump (or change the parameters for an existing dump request) with the MODIFY CATALOG,VDUMPON command. You can turn off the dump request with the MODIFY CATALOG,VDUMPOFF command. See z/OS MVS System Commands for a complete description of the MODIFY CATALOG,VDUMPON and MODIFY CATALOG,VDUMPOFF commands.

MODIFY CATALOG,VDUMPON(**,8,**,20) 

IEC351I CATALOG ADDRESS SPACE MODIFY COMMAND ACTIVE
IEC359I CATALOG REPORT VDUMP OUTPUT 503
*CAS*************************************************************
*    STATUS  FUNC CODE  RETURN CODE  COMPONENT  ERROR CODE      *
*       ON      ***         008         ***        020          *
*CAS*************************************************************
IEC352I CATALOG ADDRESS SPACE MODIFY COMMAND COMPLETED

If a dump is later generated, z/OS will issue a message similar to that generated for an automatic dump.