Add fill_device option

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index 24171e9b2f3ef7feeae341aa870155871726673c..7b717f7739664f44393d67b7b6521e8ca0404eae 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -262,6 +262,10 @@ filesize=siint     Individual file sizes. May be a range, in which case fio
                and limited to 'size' in total (if that is given). If not
                given, each created file is the same size.
 
+fill_device=bool Sets size to something really large and waits for ENOSPC (no
+               space left on device) as the terminating condition. Only makes
+                sense with sequential write.
+
 blocksize=siint
 bs=siint       The block size used for the io units. Defaults to 4k. Values
                can be given for both read and writes. If a single siint is
@@ -281,6 +285,30 @@ bsrange=irange     Instead of giving a single block size, specify a range
                writes, however a second range can be given after a comma.
                See bs=.
 
+bssplit=str    Sometimes you want even finer grained control of the
+               block sizes issued, not just an even split between them.
+               This option allows you to weight various block sizes,
+               so that you are able to define a specific amount of
+               block sizes issued. The format for this option is:
+
+                       bssplit=blocksize/percentage:blocksize/percentage
+
+               for as many block sizes as needed. So if you want to define
+               a workload that has 50% 64k blocks, 10% 4k blocks, and
+               40% 32k blocks, you would write:
+
+                       bssplit=4k/10:64k/50:32k/40
+
+               Ordering does not matter. If the percentage is left blank,
+               fio will fill in the remaining values evenly. So a bssplit
+               option like this one:
+
+                       bssplit=4k/50:1k/:32k/
+
+               would have 50% 4k ios, and 25% 1k and 32k ios. The percentages
+               always add up to 100, if bssplit is given a range that adds
+               up to more, it will error out.
+
 blocksize_unaligned
 bs_unaligned   If this option is given, any byte size value within bsrange
                may be used as a block range. This typically wont work with
@@ -861,7 +889,7 @@ Split up, the format is as follows:
                Submission latency: min, max, mean, deviation
                Completion latency: min, max, mean, deviation
                Bw: min, max, aggregate percentage of total, mean, deviation
-       CPU usage: user, system, context switches
+       CPU usage: user, system, context switches, major faults, minor faults
        IO depths: <=1, 2, 4, 8, 16, 32, >=64
        IO latencies: <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, >=2000
        Text description