HOWTO: add comment on terse and --minimal

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 7a65aa1540338c32bc2d43ef5b862b6c68b5b7ab..178bc989c8497430a7da7c2412bf3e6b3a210f47 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -172,6 +172,9 @@ a string. The following types are used:
 str    String. This is a sequence of alpha characters.
 int    Integer. A whole number value, can be negative. If prefixed with
        0x, the integer is assumed to be of base 16 (hexadecimal).
+time   Integer with possible time postfix. In seconds unless otherwise
+       specified, use eg 10m for 10 minutes. Accepts s/m/h for seconds,
+       minutes, and hours.
 siint  SI integer. A whole number value, which may contain a postfix
        describing the base of the number. Accepted postfixes are k/m/g,
        meaning kilo, mega, and giga. So if you want to specify 4096,
@@ -559,12 +562,12 @@ cpus_allowed=str Controls the same options as cpumask, but it allows a text
                setting of the permitted CPUs instead. So to use CPUs 1 and
                5, you would specify cpus_allowed=1,5.
 
-startdelay=int Start this job the specified number of seconds after fio
+startdelay=time        Start this job the specified number of seconds after fio
                has started. Only useful if the job file contains several
                jobs, and you want to delay starting some jobs to a certain
                time.
 
-runtime=int    Tell fio to terminate processing after the specified number
+runtime=time   Tell fio to terminate processing after the specified number
                of seconds. It can be quite hard to determine for how long
                a specified job will run, so this parameter is handy to
                cap the total runtime to a given time.
@@ -574,6 +577,14 @@ time_based If set, fio will run for the duration of the runtime
                written. It will simply loop over the same workload
                as many times as the runtime allows.
 
+ramp_time=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. Note
+               that the ramp_time is considered lead in time for a job,
+               thus it will increase the total runtime if a special timeout
+               or runtime is specified.
+
 invalidate=bool        Invalidate the buffer/page cache parts for this file prior
                to starting io. Defaults to true.
 
@@ -937,6 +948,8 @@ The format is one long line of values, such as:
 client1;0;0;1906777;1090804;1790;0;0;0.000000;0.000000;0;0;0.000000;0.000000;929380;1152890;25.510151%;1078276.333333;128948.113404;0;0;0;0;0;0.000000;0.000000;0;0;0.000000;0.000000;0;0;0.000000%;0.000000;0.000000;100.000000%;0.000000%;324;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%;0.0%;100.0%;0.0%;0.0%;0.0%;0.0%;0.0%
 ;0.0%;0.0%;0.0%;0.0%;0.0%
 
+To enable terse output, use the --minimal command line option.
+
 Split up, the format is as follows:
 
        jobname, groupid, error