DUMPSW

The DUMPSW system initialization parameter specifies whether you want CICS® to switch automatically to the next dump data set when the first is full.

DUMPSW={NO|NEXT|ALL}
Valid values are as follows:
NO
Disables the CICS autoswitch facility. If the transaction dump data set opened during initialization becomes full, CICS issues a console message to notify the operator. If you want to switch to the alternate data set, you must do so manually using the CEMT or EXEC CICS SET DUMPDS SWITCH command.
NEXT
Enables the autoswitch facility to switch to the next data set at end of file of the data set opened during initialization. Coding NEXT permits one switch only. If you want to switch to the alternate data set again, you must do so manually using CEMT or EXEC CICS SET DUMPDS SWITCH command. If you specify NEXT, code DD statements for both of the transaction dump data sets, DFHDMPA and DFHDMPB, in your CICS startup job stream.
ALL
Enables the autoswitch facility to switch to the inactive data set at every end of file. Specifying ALL enables continuous switching between the two dump data sets, DFHDMPA and DFHDMPB, and whenever a data set is full, it is closed and the other data set is opened.

For more information about transaction dump data sets, see Printing the transaction dump data sets.