dedupe_percentage should work even if compress_percentage is not set

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 57d3fb7f1e4de2484e071d428eab3f66de1038c4..8da5527a3edb6cbfd408f497260651d99c633be0 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -462,23 +462,26 @@ fadvise_hint=bool By default, fio will use fadvise() to advise the kernel
 
 size=int       The total size of file io for this job. Fio will run until
                this many bytes has been transferred, unless runtime is
-               limited by other options (such as 'runtime', for instance).
-               Unless specific nrfiles and filesize options are given,
-               fio will divide this size between the available files
-               specified by the job. If not set, fio will use the full
-               size of the given files or devices. If the files do not
-               exist, size must be given. It is also possible to give
-               size as a percentage between 1 and 100. If size=20% is
-               given, fio will use 20% of the full size of the given
-               files or devices.
-
+               limited by other options (such as 'runtime', for instance,
+               or increased/decreased by 'io_size'). Unless specific nrfiles
+               and filesize options are given, fio will divide this size
+               between the available files specified by the job. If not set,
+               fio will use the full size of the given files or devices.
+               If the files do not exist, size must be given. It is also
+               possible to give size as a percentage between 1 and 100. If
+               size=20% is given, fio will use 20% of the full size of the
+               given files or devices.
+
+io_size=int
 io_limit=int   Normally fio operates within the region set by 'size', which
                means that the 'size' option sets both the region and size of
                IO to be performed. Sometimes that is not what you want. With
                this option, it is possible to define just the amount of IO
                that fio should do. For instance, if 'size' is set to 20G and
-               'io_limit' is set to 5G, fio will perform IO within the first
-               20G but exit when 5G have been done.
+               'io_size' is set to 5G, fio will perform IO within the first
+               20G but exit when 5G have been done. The opposite is also
+               possible - if 'size' is set to 20G, and 'io_size' is set to
+               40G, then fio will do 40G of IO within the 0..20G region.
 
 filesize=int   Individual file sizes. May be a range, in which case fio
                will select sizes for files at random within the given range