z/OS® Component Trace (CT) supports an external writer which can be used to write trace records to a DASD or tape data set in real time. That is, as NFS generates trace records those records can be placed on DASD or tape.

Activating a CT External Writer for a program is a two-step process. These steps can be done in either order, but the external writer will not start writing out trace records until they have both been done.