+.BI merge_blktrace_scalars \fR=\fPfloat_list
+This is a percentage based option that is index paired with the list of files
+passed to \fBread_iolog\fR. When merging is performed, scale the time of each
+event by the corresponding amount. For example,
+`\-\-merge_blktrace_scalars="50:100"' runs the first trace in halftime and the
+second trace in realtime. This knob is separately tunable from
+\fBreplay_time_scale\fR which scales the trace during runtime and will not
+change the output of the merge unlike this option.
+.TP
+.BI merge_blktrace_iters \fR=\fPfloat_list
+This is a whole number option that is index paired with the list of files
+passed to \fBread_iolog\fR. When merging is performed, run each trace for
+the specified number of iterations. For example,
+`\-\-merge_blktrace_iters="2:1"' runs the first trace for two iterations
+and the second trace for one iteration.
+.TP