Fio 1.16.2

[fio.git] / HOWTO

diff --git a/HOWTO b/HOWTO
index aeb87ddb37cc59cdd057a56bd99ea9f901efbd68..5156adbe1e39c6ae738392e04467d155ee2abe57 100644 (file)
--- a/HOWTO
+++ b/HOWTO
@@ -285,6 +285,9 @@ 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
                direct IO, as that normally requires sector alignment.
 
+zero_buffers   If this option is given, fio will init the IO buffers to
+               all zeroes. The default is to fill them with random data.
+
 nrfiles=int    Number of files to use for this job. Defaults to 1.
 
 openfiles=int  Number of files to keep open at the same time. Defaults to
@@ -462,7 +465,8 @@ ratecycle=int       Average bandwidth for 'rate' and 'ratemin' over this number
 
 cpumask=int    Set the CPU affinity of this job. The parameter given is a
                bitmask of allowed CPU's the job may run on. See man
-               sched_setaffinity(2).
+               sched_setaffinity(2). This may not work on all supported
+               operating systems or kernel versions.
 
 startdelay=int Start this job the specified number of seconds after fio
                has started. Only useful if the job file contains several
@@ -474,6 +478,11 @@ runtime=int        Tell fio to terminate processing after the specified number
                a specified job will run, so this parameter is handy to
                cap the total runtime to a given time.
 
+time_based     If set, fio will run for the duration of the runtime
+               specified even if the file(s) are completey read or
+               written. It will simply loop over the same workload
+               as many times as the runtime allows.
+
 invalidate=bool        Invalidate the buffer/page cache parts for this file prior
                to starting io. Defaults to true.
 
@@ -610,7 +619,12 @@ write_iolog=str    Write the issued io patterns to the specified file. See
 
 read_iolog=str Open an iolog with the specified file name and replay the
                io patterns it contains. This can be used to store a
-               workload and replay it sometime later.
+               workload and replay it sometime later. The iolog given
+               may also be a blktrace binary file, which allows fio
+               to replay a workload captured by blktrace. See blktrace
+               for how to capture such logging data. For blktrace replay,
+               the file needs to be turned into a blkparse binary data
+               file first (blktrace <device> -d file_for_fio.bin).
 
 write_bw_log   If given, write a bandwidth log of the jobs in this job
                file. Can be used to store data of the bandwidth of the
@@ -640,6 +654,9 @@ cpuload=int If the job is a CPU cycle eater, attempt to use the specified
 cpuchunks=int  If the job is a CPU cycle eater, split the load into
                cycles of the given time. In milliseconds.
 
+disk_util=bool Generate disk utilization statistics, if the platform
+               supports it. Defaults to on.
+
 
 6.0 Interpreting the output
 ---------------------------