steadystate: make test script work better under Windows

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 9d71a96cc844c0dfa5a248d49e59f6813db254b9..6c674b27d549a28242d0dc77c5b1e5b2d6a1a06a 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -297,7 +297,7 @@ irange      Integer range with suffix. Allows value range to be given, such
        1k:4k. If the option allows two sets of ranges, they can be
        specified with a ',' or '/' delimiter: 1k-4k/8k-32k. Also see
        int.
-float_list     A list of floating numbers, separated by a ':' character.
+float_list     A list of floating point numbers, separated by a ':' character.
 
 With the above in mind, here follows the complete list of fio job
 parameters.
@@ -1214,6 +1214,48 @@ ramp_time=time   If set, fio will run the specified workload for this amount
                thus it will increase the total runtime if a special timeout
                or runtime is specified.
 
+steadystate=str:float
+ss=str:float   Define the criterion and limit for assessing steady state
+               performance. The first parameter designates the criterion
+               whereas the second parameter sets the threshold. When the
+               criterion falls below the threshold for the specified duration,
+               the job will stop. For example, iops_slope:0.1% will direct fio
+               to terminate the job when the least squares regression slope
+               falls below 0.1% of the mean IOPS. If group_reporting is
+               enabled this will apply to all jobs in the group. Below is the
+               list of available steady state assessment criteria. All
+               assessments are carried out using only data from the rolling
+               collection window. Threshold limits can be expressed as a fixed
+               value or as a percentage of the mean in the collection window.
+                       iops    Collect IOPS data. Stop the job if all
+                               individual IOPS measurements are within the
+                               specified limit of the mean IOPS (e.g., iops:2
+                               means that all individual IOPS values must be
+                               within 2 of the mean, whereas iops:0.2% means
+                               that all individual IOPS values must be within
+                               0.2% of the mean IOPS to terminate the job).
+                       iops_slope
+                               Collect IOPS data and calculate the least
+                               squares regression slope. Stop the job if the
+                               slope falls below the specified limit.
+                       bw      Collect bandwidth data. Stop the job if all
+                               individual bandwidth measurements are within
+                               the specified limit of the mean bandwidth.
+                       bw_slope
+                               Collect bandwidth data and calculate the least
+                               squares regression slope. Stop the job if the
+                               slope falls below the specified limit.
+
+steadystate_duration=time
+ss_dur=time    A rolling window of this duration will be used to judge whether
+               steady state has been reached. Data will be collected once per
+               second. The default is 0 which disables steady state detection.
+
+steadystate_ramp_time=time
+ss_ramp=time   Allow the job to run for the specified duration before
+               beginning data collection for checking the steady state job
+               termination criterion. The default is 0.
+
 invalidate=bool        Invalidate the buffer/page cache parts for this file prior
                to starting io. Defaults to true.
 
@@ -1295,7 +1337,7 @@ iopsavgtime=int   Average the calculated IOPS over the given time. Value
                through 'write_iops_log', then the minimum of this option and
                'log_avg_msec' will be used.  Default: 500ms.
 
-create_serialize=bool  If true, serialize the file creating for the jobs.
+create_serialize=bool  If true, serialize the file creation for the jobs.
                        This may be handy to avoid interleaving of data
                        files, which may greatly depend on the filesystem
                        used and even the number of processors in the system.