Option for changing log files to use Unix epoch instead of being

[fio.git] / fio.1

diff --git a/fio.1 b/fio.1
index 5e4cd4ff2663df1bff00eabcdf7382673cc5a453..8d596fb19105df2e6b3aabcbda171cf462f3157e 100644 (file)
--- a/fio.1
+++ b/fio.1
@@ -247,6 +247,11 @@ will be used if no other format specifier is given.
 .RE
 .P
 .TP
+.BI unique_filename \fR=\fPbool
+To avoid collisions between networked clients, fio defaults to prefixing
+any generated filenames (with a directory specified) with the source of
+the client connecting. To disable this behavior, set this option to 0.
+.TP
 .BI lockfile \fR=\fPstr
 Fio defaults to not locking any files before it does IO to them. If a file or
 file descriptor is shared, fio can serialize IO to that file to make the end
@@ -304,6 +309,7 @@ Trim and write mixed workload. Blocks will be trimmed first, then the same
 blocks will be written to.
 .RE
 .P
+Fio defaults to read if the option is not specified.
 For mixed I/O, the default split is 50/50. For certain types of io the result
 may still be skewed a bit, since the speed may be different. It is possible to
 specify a number of IO's to do before getting a new offset, this is done by
@@ -597,6 +603,7 @@ position the I/O location.
 .TP
 .B psync
 Basic \fBpread\fR\|(2) or \fBpwrite\fR\|(2) I/O.
+Default on all supported operating systems except for Windows.
 .TP
 .B vsync
 Basic \fBreadv\fR\|(2) or \fBwritev\fR\|(2) I/O. Will emulate queuing by
@@ -618,7 +625,7 @@ POSIX asynchronous I/O using \fBaio_read\fR\|(3) and \fBaio_write\fR\|(3).
 Solaris native asynchronous I/O.
 .TP
 .B windowsaio
-Windows native asynchronous I/O.
+Windows native asynchronous I/O. Default on Windows.
 .TP
 .B mmap
 File is memory mapped with \fBmmap\fR\|(2) and data copied using
@@ -628,9 +635,6 @@ File is memory mapped with \fBmmap\fR\|(2) and data copied using
 \fBsplice\fR\|(2) is used to transfer the data and \fBvmsplice\fR\|(2) to
 transfer data from user-space to the kernel.
 .TP
-.B syslet-rw
-Use the syslet system calls to make regular read/write asynchronous.
-.TP
 .B sg
 SCSI generic sg v3 I/O. May be either synchronous using the SG_IO ioctl, or if
 the target is an sg character device, we use \fBread\fR\|(2) and
@@ -652,7 +656,8 @@ and send/receive. This ioengine defines engine specific options.
 .TP
 .B cpuio
 Doesn't transfer any data, but burns CPU cycles according to \fBcpuload\fR and
-\fBcpucycles\fR parameters.
+\fBcpuchunks\fR parameters. A job never finishes unless there is at least one
+non-cpuio job.
 .TP
 .B guasi
 The GUASI I/O engine is the Generic Userspace Asynchronous Syscall Interface
@@ -1147,7 +1152,7 @@ Allocation method for I/O unit buffer.  Allowed values are:
 .RS
 .TP
 .B malloc
-Allocate memory with \fBmalloc\fR\|(3).
+Allocate memory with \fBmalloc\fR\|(3). Default memory type.
 .TP
 .B shm
 Use shared memory buffers allocated through \fBshmget\fR\|(2).
@@ -1241,6 +1246,9 @@ multiple times. Thus it will not work on eg network or splice IO.
 .BI unlink \fR=\fPbool
 Unlink job files when done.  Default: false.
 .TP
+.BI unlink_each_loop \fR=\fPbool
+Unlink job files after each iteration or loop.  Default: false.
+.TP
 .BI loops \fR=\fPint
 Specifies the number of iterations (runs of the same workload) of this job.
 Default: 1.
@@ -1471,6 +1479,14 @@ N is the number of jobs). Even if the filename is given, fio will still
 append the type of log. If \fBper_job_logs\fR is false, then the filename will
 not include the job index. See the \fBLOG FILE FORMATS\fR section.
 .TP
+.BI write_hist_log \fR=\fPstr
+Same as \fBwrite_lat_log\fR, but writes I/O completion latency histograms. If
+no filename is given with this option, the default filename of
+"jobname_clat_hist.x.log" is used, where x is the index of the job (1..N, where
+N is the number of jobs). Even if the filename is given, fio will still append
+the type of log. If \fBper_job_logs\fR is false, then the filename will not
+include the job index. See the \fBLOG FILE FORMATS\fR section.
+.TP
 .BI write_iops_log \fR=\fPstr
 Same as \fBwrite_bw_log\fR, but writes IOPS. If no filename is given with this
 option, the default filename of "jobname_type.x.log" is used, where x is the
@@ -1491,6 +1507,20 @@ If \fBlog_avg_msec\fR is set, fio logs the average over that window. If you
 instead want to log the maximum value, set this option to 1.  Defaults to
 0, meaning that averaged values are logged.
 .TP
+.BI log_hist_msec \fR=\fPint
+Same as \fBlog_avg_msec\fR, but logs entries for completion latency histograms.
+Computing latency percentiles from averages of intervals using \fBlog_avg_msec\fR
+is innacurate. Setting this option makes fio log histogram entries over the
+specified period of time, reducing log sizes for high IOPS devices while
+retaining percentile accuracy. See \fBlog_hist_coarseness\fR as well. Defaults
+to 0, meaning histogram logging is disabled.
+.TP
+.BI log_hist_coarseness \fR=\fPint
+Integer ranging from 0 to 6, defining the coarseness of the resolution of the
+histogram logs enabled with \fBlog_hist_msec\fR. For each increment in
+coarseness, fio outputs half as many bins. Defaults to 0, for which histogram
+logs contain 1216 latency bins. See the \fBLOG FILE FORMATS\fR section.
+.TP
 .BI log_offset \fR=\fPbool
 If this is set, the iolog options will include the byte offset for the IO
 entry as well as the other data values.
@@ -1516,6 +1546,11 @@ If set, fio will store the log files in a compressed format. They can be
 decompressed with fio, using the \fB\-\-inflate-log\fR command line parameter.
 The files will be stored with a \fB\.fz\fR suffix.
 .TP
+.BI log_unix_epoch \fR=\fPbool
+If set, fio will log Unix timestamps to the log files produced by enabling
+\fBwrite_type_log\fR for each log type, instead of the default zero-based
+timestamps.
+.TP
 .BI block_error_percentiles \fR=\fPbool
 If set, record errors in trim block-sized units from writes and trims and output
 a histogram of how many trims it took to get to errors, and what kind of error
@@ -1690,13 +1725,13 @@ Some parameters are only valid when a specific ioengine is in use. These are
 used identically to normal parameters, with the caveat that when used on the
 command line, they must come after the ioengine.
 .TP
-.BI (cpu)cpuload \fR=\fPint
+.BI (cpuio)cpuload \fR=\fPint
 Attempt to use the specified percentage of CPU cycles.
 .TP
-.BI (cpu)cpuchunks \fR=\fPint
+.BI (cpuio)cpuchunks \fR=\fPint
 Split the load into cycles of the given time. In microseconds.
 .TP
-.BI (cpu)exit_on_io_done \fR=\fPbool
+.BI (cpuio)exit_on_io_done \fR=\fPbool
 Detect when IO threads are done, then exit.
 .TP
 .BI (libaio)userspace_reap
@@ -1707,7 +1742,7 @@ from user-space to reap events. The reaping mode is only
 enabled when polling for a minimum of 0 events (eg when
 iodepth_batch_complete=0).
 .TP
-.BI (psyncv2)hipri
+.BI (pvsync2)hipri
 Set RWF_HIPRI on IO, indicating to the kernel that it's of
 higher priority than normal.
 .TP
@@ -2082,7 +2117,7 @@ This format is not supported in Fio versions => 1.20-rc3.
 .B Trace file format v2
 .RS
 The second version of the trace file format was added in Fio version 1.17.
-It allows to access more then one file per trace and has a bigger set of
+It allows one to access more then one file per trace and has a bigger set of
 possible file actions.
 
 The first line of the trace file has to be:
@@ -2297,6 +2332,13 @@ they aren't applicable if windowed logging is enabled. If windowed logging
 is enabled and \fBlog_max_value\fR is set, then fio logs maximum values in
 that window instead of averages.
 
+For histogram logging the logs look like this:
+
+.B time (msec), data direction, block-size, bin 0, bin 1, ..., bin 1215
+
+Where 'bin i' gives the frequency of IO requests with a latency falling in
+the i-th bin. See \fBlog_hist_coarseness\fR for logging fewer bins.
+
 .RE
 
 .SH CLIENT / SERVER