Two or more days is typically considered a long-term trace history interval. Long-term trace histories are best implemented with the use of generation data sets (GDSs) that are appended sequentially to form a generation data group (GDG).

A long-term trace history is preferred because some DFSMSrmm processing occurs only on a periodic basis. With a longer trace history, you might be able to see more patterns to help you perform problem analysis.