of the time specified by \fBthinktime\fR. Only valid if \fBthinktime\fR is set.
.TP
.BI thinktime_blocks \fR=\fPint
-Number of blocks to issue before waiting \fBthinktime\fR microseconds.
+Only valid if thinktime is set - control how many blocks to issue, before
+waiting \fBthinktime\fR microseconds. If not set, defaults to 1 which will
+make fio wait \fBthinktime\fR microseconds after every block. This
+effectively makes any queue depth setting redundant, since no more than 1 IO
+will be queued before we have to complete it and do our thinktime. In other
+words, this setting effectively caps the queue depth if the latter is larger.
Default: 1.
.TP
.BI rate \fR=\fPint
.TP
.BI exec_prerun \fR=\fPstr
Before running the job, execute the specified command with \fBsystem\fR\|(3).
+.RS
+Output is redirected in a file called \fBjobname.prerun.txt\fR
+.RE
.TP
.BI exec_postrun \fR=\fPstr
Same as \fBexec_prerun\fR, but the command is executed after the job completes.
+.RS
+Output is redirected in a file called \fBjobname.postrun.txt\fR
+.RE
.TP
.BI ioscheduler \fR=\fPstr
Attempt to switch the device hosting the file to the specified I/O scheduler.