Add ramp_time option
Sometimes it's useful to let a job settle for a little while
before taking any measurements on latency and throughput, since
the initial rate on eg a write workload may be much higher than
the longer sustained rate.
So add a ramp_time option that allows the user to specify a lead
ramp time that must have passed before fio takes any performance
numbers into account.
Suggested by "Jenkins, Lee" <Lee.Jenkins@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/HOWTO b/HOWTO
index 7a65aa1..dd2f84a 100644
--- a/HOWTO
+++ b/HOWTO
@@ -574,6 +574,11 @@
written. It will simply loop over the same workload
as many times as the runtime allows.
+ramp_time If set, fio will run the specified workload for this amount
+ of time before logging any performance numbers. Useful for
+ letting performance settle before logging results, thus
+ minimizing the runtime required for stable results.
+
invalidate=bool Invalidate the buffer/page cache parts for this file prior
to starting io. Defaults to true.