Add support for modifying the randomness of a workload

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 64453489175aec0346e8e8f7df9422849582fc12..8211c3b48166cd6f03e4f32d9beddf57cf1e03e2 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -766,6 +766,17 @@ random_distribution=str:float      By default, fio will use a completely uniform
                random_distribution=zipf:1.2 as the option. If a non-uniform
                model is used, fio will disable use of the random map.
 
+percentage_random=int  For a random workload, set how big a percentage should
+               be random. This defaults to 100%, in which case the workload
+               is fully random. It can be set from anywhere from 0 to 100.
+               Setting it to 0 would make the workload fully sequential. Any
+               setting in between will result in a random mix of sequential
+               and random IO, at the given percentages.
+       
+percentage_sequential=int      See percentage_random. It is guaranteed that
+               they add up to 100. The later setting has priority, each
+               will adjust the other.
+
 norandommap    Normally fio will cover every block of the file when doing
                random IO. If this option is given, fio will just get a
                new random offset without looking at past io history. This