-.TH fio 1 "June 2017" "User Manual"
+.TH fio 1 "July 2017" "User Manual"
.SH NAME
fio \- flexible I/O tester
.SH SYNOPSIS
.TP
.BI \-\-debug \fR=\fPtype
Enable verbose tracing of various fio actions. May be `all' for all types
-or individual types separated by a comma (eg \-\-debug=io,file). `help' will
-list all available tracing options.
+or individual types separated by a comma (e.g. \-\-debug=file,mem will enable
+file and memory debugging). `help' will list all available tracing options.
+.TP
+.BI \-\-parse-only
+Parse options only, don't start any I/O.
.TP
.BI \-\-output \fR=\fPfilename
Write output to \fIfilename\fR.
Print statistics in selected mode AND terse, semicolon-delimited format.
Deprecated, use \-\-output-format instead to select multiple formats.
.TP
-.B \-\-version
-Display version information and exit.
-.TP
.BI \-\-terse\-version \fR=\fPversion
Set terse version output format (default 3, or 2, 4, 5)
.TP
+.B \-\-version
+Print version information and exit.
+.TP
.B \-\-help
-Display usage information and exit.
+Print a summary of the command line options and exit.
.TP
.B \-\-cpuclock-test
-Perform test and validation of internal CPU clock
+Perform test and validation of internal CPU clock.
.TP
-.BI \-\-crctest[\fR=\fPtest]
-Test the speed of the builtin checksumming functions. If no argument is given,
-all of them are tested. Or a comma separated list can be passed, in which
+.BI \-\-crctest \fR=\fP[test]
+Test the speed of the built-in checksumming functions. If no argument is given,
+all of them are tested. Alternatively, a comma separated list can be passed, in which
case the given ones are tested.
.TP
.BI \-\-cmdhelp \fR=\fPcommand
-Print help information for \fIcommand\fR. May be `all' for all commands.
+Print help information for \fIcommand\fR. May be `all' for all commands.
.TP
.BI \-\-enghelp \fR=\fPioengine[,command]
List all commands defined by \fIioengine\fR, or print help for \fIcommand\fR defined by \fIioengine\fR.
+If no \fIioengine\fR is given, list all available ioengines.
.TP
.BI \-\-showcmd \fR=\fPjobfile
Convert \fIjobfile\fR to a set of command-line options.
.TP
+.BI \-\-readonly
+Turn on safety read-only checks, preventing writes. The \-\-readonly
+option is an extra safety guard to prevent users from accidentally starting
+a write workload when that is not desired. Fio will only write if
+`rw=write/randwrite/rw/randrw` is given. This extra safety net can be used
+as an extra precaution as \-\-readonly will also enable a write check in
+the I/O engine core to prevent writes due to unknown user space bug(s).
+.TP
.BI \-\-eta \fR=\fPwhen
-Specifies when real-time ETA estimate should be printed. \fIwhen\fR may
-be one of `always', `never' or `auto'.
+Specifies when real-time ETA estimate should be printed. \fIwhen\fR may
+be `always', `never' or `auto'.
.TP
.BI \-\-eta\-newline \fR=\fPtime
-Force an ETA newline for every `time` period passed.
+Force a new line for every \fItime\fR period passed. When the unit is omitted,
+the value is interpreted in seconds.
.TP
.BI \-\-status\-interval \fR=\fPtime
-Report full output status every `time` period passed.
-.TP
-.BI \-\-readonly
-Turn on safety read-only checks, preventing any attempted write.
-.TP
-.BI \-\-section \fR=\fPsec
-Only run section \fIsec\fR from job file. This option can be used multiple times to add more sections to run.
+Force full status dump every \fItime\fR period passed. When the unit is omitted,
+the value is interpreted in seconds.
+.TP
+.BI \-\-section \fR=\fPname
+Only run specified section \fIname\fR in job file. Multiple sections can be specified.
+The \-\-section option allows one to combine related jobs into one file.
+E.g. one job file could define light, moderate, and heavy sections. Tell
+fio to run only the "heavy" section by giving \-\-section=heavy
+command line option. One can also specify the "write" operations in one
+section and "verify" operation in another section. The \-\-section option
+only applies to job sections. The reserved *global* section is always
+parsed and used.
.TP
.BI \-\-alloc\-size \fR=\fPkb
-Set the internal smalloc pool size to \fIkb\fP kilobytes.
+Set the internal smalloc pool size to \fIkb\fP in KiB. The
+\-\-alloc-size switch allows one to use a larger pool size for smalloc.
+If running large jobs with randommap enabled, fio can run out of memory.
+Smalloc is an internal allocator for shared structures from a fixed size
+memory pool and can grow to 16 pools. The pool size defaults to 16MiB.
+NOTE: While running .fio_smalloc.* backing store files are visible
+in /tmp.
.TP
.BI \-\-warnings\-fatal
All fio parser warnings are fatal, causing fio to exit with an error.
.TP
.BI \-\-max\-jobs \fR=\fPnr
-Set the maximum allowed number of jobs (threads/processes) to support.
+Set the maximum number of threads/processes to support.
.TP
.BI \-\-server \fR=\fPargs
-Start a backend server, with \fIargs\fP specifying what to listen to. See client/server section.
+Start a backend server, with \fIargs\fP specifying what to listen to. See Client/Server section.
.TP
.BI \-\-daemonize \fR=\fPpidfile
-Background a fio server, writing the pid to the given pid file.
+Background a fio server, writing the pid to the given \fIpidfile\fP file.
.TP
-.BI \-\-client \fR=\fPhost
-Instead of running the jobs locally, send and run them on the given host or set of hosts. See client/server section.
+.BI \-\-client \fR=\fPhostname
+Instead of running the jobs locally, send and run them on the given host or set of hosts. See Client/Server section.
+.TP
+.BI \-\-remote-config \fR=\fPfile
+Tell fio server to load this local file.
.TP
.BI \-\-idle\-prof \fR=\fPoption
-Report cpu idleness on a system or percpu basis (\fIoption\fP=system,percpu) or run unit work calibration only (\fIoption\fP=calibrate).
+Report CPU idleness. \fIoption\fP is one of the following:
+.RS
+.RS
+.TP
+.B calibrate
+Run unit work calibration only and exit.
+.TP
+.B system
+Show aggregate system idleness and unit work.
+.TP
+.B percpu
+As "system" but also show per CPU idleness.
+.RE
+.RE
+.TP
+.BI \-\-inflate-log \fR=\fPlog
+Inflate and output compressed log.
+.TP
+.BI \-\-trigger-file \fR=\fPfile
+Execute trigger cmd when file exists.
+.TP
+.BI \-\-trigger-timeout \fR=\fPt
+Execute trigger at this time.
+.TP
+.BI \-\-trigger \fR=\fPcmd
+Set this command as local trigger.
+.TP
+.BI \-\-trigger-remote \fR=\fPcmd
+Set this command as remote trigger.
+.TP
+.BI \-\-aux-path \fR=\fPpath
+Use this path for fio state generated files.
.SH "JOB FILE FORMAT"
-Job files are in `ini' format. They consist of one or more
-job definitions, which begin with a job name in square brackets and
-extend to the next job name. The job name can be any ASCII string
-except `global', which has a special meaning. Following the job name is
-a sequence of zero or more parameters, one per line, that define the
-behavior of the job. Any line starting with a `;' or `#' character is
-considered a comment and ignored.
-.P
-If \fIjobfile\fR is specified as `-', the job file will be read from
-standard input.
-.SS "Global Section"
-The global section contains default parameters for jobs specified in the
-job file. A job is only affected by global sections residing above it,
-and there may be any number of global sections. Specific job definitions
-may override any parameter set in global sections.
-.SH "JOB PARAMETERS"
-.SS Types
-Some parameters may take arguments of a specific type.
-Anywhere a numeric value is required, an arithmetic expression may be used,
-provided it is surrounded by parentheses. Supported operators are:
+Any parameters following the options will be assumed to be job files, unless
+they match a job file parameter. Multiple job files can be listed and each job
+file will be regarded as a separate group. Fio will `stonewall` execution
+between each group.
+
+Fio accepts one or more job files describing what it is
+supposed to do. The job file format is the classic ini file, where the names
+enclosed in [] brackets define the job name. You are free to use any ASCII name
+you want, except *global* which has special meaning. Following the job name is
+a sequence of zero or more parameters, one per line, that define the behavior of
+the job. If the first character in a line is a ';' or a '#', the entire line is
+discarded as a comment.
+
+A *global* section sets defaults for the jobs described in that file. A job may
+override a *global* section parameter, and a job file may even have several
+*global* sections if so desired. A job is only affected by a *global* section
+residing above it.
+
+The \-\-cmdhelp option also lists all options. If used with an `option`
+argument, \-\-cmdhelp will detail the given `option`.
+
+See the `examples/` directory in the fio source for inspiration on how to write
+job files. Note the copyright and license requirements currently apply to
+`examples/` files.
+.SH "JOB FILE PARAMETERS"
+Some parameters take an option of a given type, such as an integer or a
+string. Anywhere a numeric value is required, an arithmetic expression may be
+used, provided it is surrounded by parentheses. Supported operators are:
.RS
.RS
.TP
.P
For time values in expressions, units are microseconds by default. This is
different than for time values not in expressions (not enclosed in
-parentheses). The types used are:
+parentheses).
+.SH "PARAMETER TYPES"
+The following parameter types are used.
.TP
.I str
-String: a sequence of alphanumeric characters.
+String. A sequence of alphanumeric characters.
+.TP
+.I time
+Integer with possible time suffix. Without a unit value is interpreted as
+seconds unless otherwise specified. Accepts a suffix of 'd' for days, 'h' for
+hours, 'm' for minutes, 's' for seconds, 'ms' (or 'msec') for milliseconds and 'us'
+(or 'usec') for microseconds. For example, use 10m for 10 minutes.
.TP
.I int
Integer. A whole number value, which may contain an integer prefix
and an integer suffix.
-[integer prefix]number[integer suffix]
+[*integer prefix*] **number** [*integer suffix*]
+
+The optional *integer prefix* specifies the number's base. The default
+is decimal. *0x* specifies hexadecimal.
-The optional integer prefix specifies the number's base. The default
-is decimal. 0x specifies hexadecimal.
+The optional *integer suffix* specifies the number's units, and includes an
+optional unit prefix and an optional unit. For quantities of data, the
+default unit is bytes. For quantities of time, the default unit is seconds
+unless otherwise specified.
-The optional integer suffix specifies the number's units, and includes
-an optional unit prefix and an optional unit. For quantities
-of data, the default unit is bytes. For quantities of time,
-the default unit is seconds.
+With \fBkb_base=1000\fR, fio follows international standards for unit
+prefixes. To specify power-of-10 decimal values defined in the
+International System of Units (SI):
-With \fBkb_base=1000\fR, fio follows international standards for unit prefixes.
-To specify power-of-10 decimal values defined in the International
-System of Units (SI):
.nf
ki means kilo (K) or 1000
mi means mega (M) or 1000**2
.fi
To specify power-of-2 binary values defined in IEC 80000-13:
+
.nf
k means kibi (Ki) or 1024
m means mebi (Mi) or 1024**2
p means pebi (Pi) or 1024**5
.fi
-With \fBkb_base=1024\fR (the default), the unit prefixes are opposite from
-those specified in the SI and IEC 80000-13 standards to provide
-compatibility with old scripts. For example, 4k means 4096.
+With \fBkb_base=1024\fR (the default), the unit prefixes are opposite
+from those specified in the SI and IEC 80000-13 standards to provide
+compatibility with old scripts. For example, 4k means 4096.
+
+For quantities of data, an optional unit of 'B' may be included
+(e.g., 'kB' is the same as 'k').
+
+The *integer suffix* is not case sensitive (e.g., m/mi mean mebi/mega,
+not milli). 'b' and 'B' both mean byte, not bit.
-.nf
Examples with \fBkb_base=1000\fR:
+
+.nf
4 KiB: 4096, 4096b, 4096B, 4k, 4kb, 4kB, 4K, 4KB
1 MiB: 1048576, 1m, 1024k
1 MB: 1000000, 1mi, 1000ki
1 TB: 1000000000, 1ti, 1000mi, 1000000ki
.fi
-.nf
Examples with \fBkb_base=1024\fR (default):
+
+.nf
4 KiB: 4096, 4096b, 4096B, 4k, 4kb, 4kB, 4K, 4KB
1 MiB: 1048576, 1m, 1024k
1 MB: 1000000, 1mi, 1000ki
1 TB: 1000000000, 1ti, 1000mi, 1000000ki
.fi
-For quantities of data, an optional unit of 'B' may be included
-(e.g., 'kb' is the same as 'k').
-
-The integer suffix is not case sensitive (e.g., m/mi mean mebi/mega,
-not milli). 'b' and 'B' both mean byte, not bit.
-
To specify times (units are not case sensitive):
+
.nf
D means days
H means hours
us or usec means microseconds
.fi
+If the option accepts an upper and lower range, use a colon ':' or
+minus '-' to separate such values. See `irange` parameter type.
+If the lower value specified happens to be larger than the upper value
+the two values are swapped.
.TP
.I bool
-Boolean: a true or false value. `0' denotes false, `1' denotes true.
+Boolean. Usually parsed as an integer, however only defined for
+true and false (1 and 0).
.TP
.I irange
-Integer range: a range of integers specified in the format
-\fIlower\fR:\fIupper\fR or \fIlower\fR\-\fIupper\fR. \fIlower\fR and
-\fIupper\fR may contain a suffix as described above. If an option allows two
-sets of ranges, they are separated with a `,' or `/' character. For example:
-`8\-8k/8M\-4G'.
+Integer range with suffix. Allows value range to be given, such as
+1024-4096. A colon may also be used as the separator, e.g. 1k:4k. If the
+option allows two sets of ranges, they can be specified with a ',' or '/'
+delimiter: 1k-4k/8k-32k. Also see `int` parameter type.
.TP
.I float_list
-List of floating numbers: A list of floating numbers, separated by
-a ':' character.
-.SS "Parameter List"
+A list of floating point numbers, separated by a ':' character.
+.SH "JOB DESCRIPTION"
+With the above in mind, here follows the complete list of fio job parameters.
.TP
.BI name \fR=\fPstr
May be used to override the job name. On the command line, this parameter
.B none
Do not pre-allocate space.
.TP
+.B native
+Use a platform's native pre-allocation call but fall back to 'none' behavior if
+it fails/is not implemented.
+.TP
.B posix
Pre-allocate via \fBposix_fallocate\fR\|(3).
.TP
.RE
.P
May not be available on all supported platforms. 'keep' is only
-available on Linux. If using ZFS on Solaris this must be set to 'none'
-because ZFS doesn't support it. Default: 'posix'.
+available on Linux. If using ZFS on Solaris this cannot be set to 'posix'
+because ZFS doesn't support it. Default: 'native' if any pre-allocation methods
+are available, 'none' if not.
.RE
.TP
.BI fadvise_hint \fR=\fPstr
.RE
.RE
.TP
-.BI fadvise_stream \fR=\fPint
-Use \fBposix_fadvise\fR\|(2) to advise the kernel what stream ID the
-writes issued belong to. Only supported on Linux. Note, this option
-may change going forward.
+.BI write_hint \fR=\fPstr
+Use \fBfcntl\fR\|(2) to advise the kernel what life time to expect from a write.
+Only supported on Linux, as of version 4.13. The values are all relative to
+each other, and no absolute meaning should be associated with them. Accepted
+values are:
+.RS
+.RS
+.TP
+.B none
+No particular life time associated with this file.
+.TP
+.B short
+Data written to this file has a short life time.
+.TP
+.B medium
+Data written to this file has a medium life time.
+.TP
+.B long
+Data written to this file has a long life time.
+.TP
+.B extreme
+Data written to this file has a very long life time.
+.RE
+.RE
.TP
.BI size \fR=\fPint
Total size of I/O for this job. \fBfio\fR will run until this many bytes have
SYNC_FILE_RANGE_WRITE
.TP
.B wait_after
-SYNC_FILE_RANGE_WRITE
+SYNC_FILE_RANGE_WAIT_AFTER
.TP
.RE
.P
30% of accesses should be to the next 20%
.RE
.RS
-8% of accesses should be to to the next 30%
+8% of accesses should be to the next 30%
.RE
.RS
2% of accesses should be to the next 40%
on documentation by Jens Axboe.
.SH "REPORTING BUGS"
Report bugs to the \fBfio\fR mailing list <fio@vger.kernel.org>.
-See \fBREADME\fR.
+.br
+See \fBREPORTING-BUGS\fR.
+
+\fBREPORTING-BUGS\fR: http://git.kernel.dk/cgit/fio/plain/REPORTING-BUGS
.SH "SEE ALSO"
For further documentation see \fBHOWTO\fR and \fBREADME\fR.
.br