-.TH fio 1 "September 2007" "User Manual"
+.TH fio 1 "June 2017" "User Manual"
.SH NAME
fio \- flexible I/O tester
.SH SYNOPSIS
.BI \-\-output \fR=\fPfilename
Write output to \fIfilename\fR.
.TP
+.BI \-\-output-format \fR=\fPformat
+Set the reporting format to \fInormal\fR, \fIterse\fR, \fIjson\fR, or
+\fIjson+\fR. Multiple formats can be selected, separate by a comma. \fIterse\fR
+is a CSV based format. \fIjson+\fR is like \fIjson\fR, except it adds a full
+dump of the latency buckets.
+.TP
.BI \-\-runtime \fR=\fPruntime
Limit run time to \fIruntime\fR seconds.
.TP
-.B \-\-latency\-log
-Generate per-job latency logs.
-.TP
.B \-\-bandwidth\-log
-Generate per-job bandwidth logs.
+Generate aggregate bandwidth logs.
.TP
.B \-\-minimal
Print statistics in a terse, semicolon-delimited format.
.TP
+.B \-\-append-terse
+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 (Current version 3, or older version 2).
+Set terse version output format (default 3, or 2, 4, 5)
.TP
.B \-\-help
Display usage information and exit.
.TP
+.B \-\-cpuclock-test
+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
+case the given ones are tested.
+.TP
.BI \-\-cmdhelp \fR=\fPcommand
Print help information for \fIcommand\fR. May be `all' for all commands.
.TP
Specifies when real-time ETA estimate should be printed. \fIwhen\fR may
be one of `always', `never' or `auto'.
.TP
+.BI \-\-eta\-newline \fR=\fPtime
+Force an ETA newline for every `time` period passed.
+.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. Multiple of these options can be given, adding more sections to run.
+Only run section \fIsec\fR from job file. This option can be used multiple times to add more sections to run.
.TP
.BI \-\-alloc\-size \fR=\fPkb
Set the internal smalloc pool size to \fIkb\fP kilobytes.
Background a fio server, writing the pid to the given pid file.
.TP
.BI \-\-client \fR=\fPhost
-Instead of running the jobs locally, send and run them on the given host.
+Instead of running the jobs locally, send and run them on the given host or set of hosts. See client/server section.
.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).
may override any parameter set in global sections.
.SH "JOB PARAMETERS"
.SS Types
-Some parameters may take arguments of a specific type. The types used are:
+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:
+.RS
+.RS
+.TP
+.B addition (+)
+.TP
+.B subtraction (-)
+.TP
+.B multiplication (*)
+.TP
+.B division (/)
+.TP
+.B modulus (%)
+.TP
+.B exponentiation (^)
+.RE
+.RE
+.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:
.TP
.I str
String: a sequence of alphanumeric characters.
.TP
.I int
-SI integer: a whole number, possibly containing a suffix denoting the base unit
-of the value. Accepted suffixes are `k', 'M', 'G', 'T', and 'P', denoting
-kilo (1024), mega (1024^2), giga (1024^3), tera (1024^4), and peta (1024^5)
-respectively. The suffix is not case sensitive. If prefixed with '0x', the
-value is assumed to be base 16 (hexadecimal). A suffix may include a trailing 'b',
-for instance 'kb' is identical to 'k'. You can specify a base 10 value
-by using 'KiB', 'MiB', 'GiB', etc. This is useful for disk drives where
-values are often given in base 10 values. Specifying '30GiB' will get you
-30*1000^3 bytes.
+Integer. A whole number value, which may contain an integer prefix
+and an 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 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):
+.nf
+ki means kilo (K) or 1000
+mi means mega (M) or 1000**2
+gi means giga (G) or 1000**3
+ti means tera (T) or 1000**4
+pi means peta (P) or 1000**5
+.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
+g means gibi (Gi) or 1024**3
+t means tebi (Ti) or 1024**4
+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.
+
+.nf
+Examples with \fBkb_base=1000\fR:
+4 KiB: 4096, 4096b, 4096B, 4k, 4kb, 4kB, 4K, 4KB
+1 MiB: 1048576, 1m, 1024k
+1 MB: 1000000, 1mi, 1000ki
+1 TiB: 1073741824, 1t, 1024m, 1048576k
+1 TB: 1000000000, 1ti, 1000mi, 1000000ki
+.fi
+
+.nf
+Examples with \fBkb_base=1024\fR (default):
+4 KiB: 4096, 4096b, 4096B, 4k, 4kb, 4kB, 4K, 4KB
+1 MiB: 1048576, 1m, 1024k
+1 MB: 1000000, 1mi, 1000ki
+1 TiB: 1073741824, 1t, 1024m, 1048576k
+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
+M mean minutes
+s or sec means seconds (default)
+ms or msec means milliseconds
+us or usec means microseconds
+.fi
+
.TP
.I bool
Boolean: a true or false value. `0' denotes false, `1' denotes true.
.TP
.I float_list
List of floating numbers: A list of floating numbers, separated by
-a ':' charcater.
+a ':' character.
.SS "Parameter List"
.TP
.BI name \fR=\fPstr
May be used to override the job name. On the command line, this parameter
has the special purpose of signalling the start of a new job.
.TP
+.BI wait_for \fR=\fPstr
+Specifies the name of the already defined job to wait for. Single waitee name
+only may be specified. If set, the job won't be started until all workers of
+the waitee job are done. Wait_for operates on the job name basis, so there are
+a few limitations. First, the waitee must be defined prior to the waiter job
+(meaning no forward references). Second, if a job is being referenced as a
+waitee, it must have a unique name (no duplicate waitees).
+.TP
.BI description \fR=\fPstr
Human-readable description of the job. It is printed when the job is run, but
otherwise has no special purpose.
.BI directory \fR=\fPstr
Prefix filenames with this directory. Used to place files in a location other
than `./'.
+You can specify a number of directories by separating the names with a ':'
+character. These directories will be assigned equally distributed to job clones
+creates with \fInumjobs\fR as long as they are using generated filenames.
+If specific \fIfilename(s)\fR are set fio will use the first listed directory,
+and thereby matching the \fIfilename\fR semantic which generates a file each
+clone if not specified, but let all clones use the same if set. See
+\fIfilename\fR for considerations regarding escaping certain characters on
+some platforms.
.TP
.BI filename \fR=\fPstr
.B fio
If the I/O engine is file-based, you can specify
a number of files by separating the names with a `:' character. `\-' is a
reserved name, meaning stdin or stdout, depending on the read/write direction
-set.
+set. On Windows, disk devices are accessed as \\.\PhysicalDrive0 for the first
+device, \\.\PhysicalDrive1 for the second etc. Note: Windows and FreeBSD
+prevent write access to areas of the disk containing in-use data
+(e.g. filesystems). If the wanted filename does need to include a colon, then
+escape that with a '\\' character. For instance, if the filename is
+"/dev/dsk/foo@3,0:c", then you would use filename="/dev/dsk/foo@3,0\\:c".
.TP
.BI filename_format \fR=\fPstr
-.B If sharing multiple files between jobs, it is usually necessary to have
+If sharing multiple files between jobs, it is usually necessary to have
fio generate the exact names that you want. By default, fio will name a file
based on the default file format specification of
\fBjobname.jobnumber.filenumber\fP. With this option, that can be
.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
No locking. This is the default.
.TP
.B exclusive
-Only one thread or process may do IO at the time, excluding all others.
+Only one thread or process may do IO at a time, excluding all others.
.TP
.B readwrite
Read-write locking on the file. Many readers may access the file at the same
time, but writes get exclusive access.
.RE
+.RE
.P
.BI opendir \fR=\fPstr
Recursively open any files below directory \fIstr\fR.
.B write
Sequential writes.
.TP
+.B trim
+Sequential trims (Linux block devices only).
+.TP
.B randread
Random reads.
.TP
.B randwrite
Random writes.
.TP
+.B randtrim
+Random trims (Linux block devices only).
+.TP
.B rw, readwrite
Mixed sequential reads and writes.
.TP
-.B randrw
+.B randrw
Mixed random reads and writes.
+.TP
+.B trimwrite
+Sequential 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
.BI kb_base \fR=\fPint
The base unit for a kilobyte. The defacto base is 2^10, 1024. Storage
manufacturers like to use 10^3 or 1000 as a base ten unit instead, for obvious
-reasons. Allow values are 1024 or 1000, with 1024 being the default.
+reasons. Allowed values are 1024 or 1000, with 1024 being the default.
.TP
.BI unified_rw_reporting \fR=\fPbool
Fio normally reports statistics on a per data direction basis, meaning that
-read, write, and trim are accounted and reported separately. If this option is
-set, the fio will sum the results and report them as "mixed" instead.
+reads, writes, and trims are accounted and reported separately. If this option is
+set fio sums the results and reports them as "mixed" instead.
.TP
.BI randrepeat \fR=\fPbool
-Seed the random number generator in a predictable way so results are repeatable
-across runs. Default: true.
+Seed the random number generator used for random I/O patterns in a predictable
+way so the pattern is repeatable across runs. Default: true.
+.TP
+.BI allrandrepeat \fR=\fPbool
+Seed all random number generators in a predictable way so results are
+repeatable across runs. Default: false.
.TP
-.BI use_os_rand \fR=\fPbool
-Fio can either use the random generator supplied by the OS to generator random
-offsets, or it can use it's own internal generator (based on Tausworthe).
-Default is to use the internal generator, which is often of better quality and
-faster. Default: false.
+.BI randseed \fR=\fPint
+Seed the random number generators based on this seed value, to be able to
+control what sequence of output is being generated. If not set, the random
+sequence depends on the \fBrandrepeat\fR setting.
.TP
.BI fallocate \fR=\fPstr
Whether pre-allocation is performed when laying down files. Accepted values
Do not pre-allocate space.
.TP
.B posix
-Pre-allocate via posix_fallocate().
+Pre-allocate via \fBposix_fallocate\fR\|(3).
.TP
.B keep
-Pre-allocate via fallocate() with FALLOC_FL_KEEP_SIZE set.
+Pre-allocate via \fBfallocate\fR\|(2) with FALLOC_FL_KEEP_SIZE set.
.TP
.B 0
Backward-compatible alias for 'none'.
because ZFS doesn't support it. Default: 'posix'.
.RE
.TP
-.BI fadvise_hint \fR=\fPbool
-Use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
-are likely to be issued. Default: true.
+.BI fadvise_hint \fR=\fPstr
+Use \fBposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
+are likely to be issued. Accepted values are:
+.RS
+.RS
+.TP
+.B 0
+Backwards compatible hint for "no hint".
+.TP
+.B 1
+Backwards compatible hint for "advise with fio workload type". This
+uses \fBFADV_RANDOM\fR for a random workload, and \fBFADV_SEQUENTIAL\fR
+for a sequential workload.
+.TP
+.B sequential
+Advise using \fBFADV_SEQUENTIAL\fR
+.TP
+.B random
+Advise using \fBFADV_RANDOM\fR
+.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.
.TP
.BI size \fR=\fPint
Total size of I/O for this job. \fBfio\fR will run until this many bytes have
-been transfered, unless limited by other options (\fBruntime\fR, for instance).
-Unless \fBnrfiles\fR and \fBfilesize\fR options are given, this amount will be
-divided between the available files for the job. If not set, fio will use the
-full size of the given files or devices. If the 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.
+been transferred, unless limited by other options (\fBruntime\fR, for instance,
+or increased/descreased by \fBio_size\fR). Unless \fBnrfiles\fR and
+\fBfilesize\fR options are given, this amount will be divided between the
+available files for 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.
+.TP
+.BI io_size \fR=\fPint "\fR,\fB io_limit \fR=\fPint
+Normally fio operates within the region set by \fBsize\fR, which means that
+the \fBsize\fR 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 \fBsize\fR
+is set to 20G and \fBio_limit\fR 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 \fBsize\fR is set to 20G, and \fBio_size\fR is set to 40G, then
+fio will do 40G of IO within the 0..20G region.
.TP
.BI fill_device \fR=\fPbool "\fR,\fB fill_fs" \fR=\fPbool
Sets size to something really large and waits for ENOSPC (no space left on
that is given). If \fBfilesize\fR is not specified, each created file is the
same size.
.TP
-.BI blocksize \fR=\fPint[,int] "\fR,\fB bs" \fR=\fPint[,int]
-Block size for I/O units. Default: 4k. Values for reads and writes can be
-specified separately in the format \fIread\fR,\fIwrite\fR, either of
-which may be empty to leave that value at its default.
-.TP
-.BI blocksize_range \fR=\fPirange[,irange] "\fR,\fB bsrange" \fR=\fPirange[,irange]
-Specify a range of I/O block sizes. The issued I/O unit will always be a
-multiple of the minimum size, unless \fBblocksize_unaligned\fR is set. Applies
-to both reads and writes if only one range is given, but can be specified
-separately with a comma seperating the values. Example: bsrange=1k-4k,2k-8k.
-Also (see \fBblocksize\fR).
-.TP
-.BI bssplit \fR=\fPstr
+.BI file_append \fR=\fPbool
+Perform IO after the end of the file. Normally fio will operate within the
+size of a file. If this option is set, then fio will append to the file
+instead. This has identical behavior to setting \fRoffset\fP to the size
+of a file. This option is ignored on non-regular files.
+.TP
+.BI blocksize \fR=\fPint[,int][,int] "\fR,\fB bs" \fR=\fPint[,int][,int]
+The block size in bytes for I/O units. Default: 4096.
+A single value applies to reads, writes, and trims.
+Comma-separated values may be specified for reads, writes, and trims.
+Empty values separated by commas use the default value. A value not
+terminated in a comma applies to subsequent types.
+.nf
+Examples:
+bs=256k means 256k for reads, writes and trims
+bs=8k,32k means 8k for reads, 32k for writes and trims
+bs=8k,32k, means 8k for reads, 32k for writes, and default for trims
+bs=,8k means default for reads, 8k for writes and trims
+bs=,8k, means default for reads, 8k for writes, and default for trims
+.fi
+.TP
+.BI blocksize_range \fR=\fPirange[,irange][,irange] "\fR,\fB bsrange" \fR=\fPirange[,irange][,irange]
+A range of block sizes in bytes for I/O units.
+The issued I/O unit will always be a multiple of the minimum size, unless
+\fBblocksize_unaligned\fR is set.
+Comma-separated ranges may be specified for reads, writes, and trims
+as described in \fBblocksize\fR.
+.nf
+Example: bsrange=1k-4k,2k-8k.
+.fi
+.TP
+.BI bssplit \fR=\fPstr[,str][,str]
This option allows even finer grained control of the block sizes issued,
not just even splits between them. With this option, you can weight various
block sizes for exact control of the issued IO for a job that has mixed
optionally adding as many definitions as needed separated by a colon.
Example: bssplit=4k/10:64k/50:32k/40 would issue 50% 64k blocks, 10% 4k
blocks and 40% 32k blocks. \fBbssplit\fR also supports giving separate
-splits to reads and writes. The format is identical to what the
-\fBbs\fR option accepts, the read and write parts are separated with a
-comma.
+splits to reads, writes, and trims.
+Comma-separated values may be specified for reads, writes, and trims
+as described in \fBblocksize\fR.
.TP
-.B blocksize_unaligned\fR,\fP bs_unaligned
-If set, any size in \fBblocksize_range\fR may be used. This typically won't
+.B blocksize_unaligned\fR,\fB bs_unaligned
+If set, fio will issue I/O units with any size within \fBblocksize_range\fR,
+not just multiples of the minimum size. This typically won't
work with direct I/O, as that normally requires sector alignment.
.TP
-.BI blockalign \fR=\fPint[,int] "\fR,\fB ba" \fR=\fPint[,int]
-At what boundary to align random IO offsets. Defaults to the same as 'blocksize'
-the minimum blocksize given. Minimum alignment is typically 512b
-for using direct IO, though it usually depends on the hardware block size.
-This option is mutually exclusive with using a random map for files, so it
-will turn off that option.
+.BI bs_is_seq_rand \fR=\fPbool
+If this option is set, fio will use the normal read,write blocksize settings as
+sequential,random blocksize settings instead. Any random read or write will
+use the WRITE blocksize settings, and any sequential read or write will use
+the READ blocksize settings.
+.TP
+.BI blockalign \fR=\fPint[,int][,int] "\fR,\fB ba" \fR=\fPint[,int][,int]
+Boundary to which fio will align random I/O units. Default: \fBblocksize\fR.
+Minimum alignment is typically 512b for using direct IO, though it usually
+depends on the hardware block size. This option is mutually exclusive with
+using a random map for files, so it will turn off that option.
+Comma-separated values may be specified for reads, writes, and trims
+as described in \fBblocksize\fR.
.TP
.B zero_buffers
-Initialise buffers with all zeros. Default: fill buffers with random data.
+Initialize buffers with all zeros. Default: fill buffers with random data.
.TP
.B refill_buffers
If this option is given, fio will refill the IO buffers on every submit. The
.BI buffer_compress_percentage \fR=\fPint
If this is set, then fio will attempt to provide IO buffer content (on WRITEs)
that compress to the specified level. Fio does this by providing a mix of
-random data and zeroes. Note that this is per block size unit, for file/disk
-wide compression level that matches this setting, you'll also want to set
-\fBrefill_buffers\fR.
+random data and a fixed pattern. The fixed pattern is either zeroes, or the
+pattern specified by \fBbuffer_pattern\fR. If the pattern option is used, it
+might skew the compression ratio slightly. Note that this is per block size
+unit, for file/disk wide compression level that matches this setting. Note
+that this is per block size unit, for file/disk wide compression level that
+matches this setting, you'll also want to set refill_buffers.
.TP
.BI buffer_compress_chunk \fR=\fPint
See \fBbuffer_compress_percentage\fR. This setting allows fio to manage how
the remaining zeroed. With this set to some chunk size smaller than the block
size, fio can alternate random and zeroed data throughout the IO buffer.
.TP
+.BI buffer_pattern \fR=\fPstr
+If set, fio will fill the I/O buffers with this pattern or with the contents
+of a file. If not set, the contents of I/O buffers are defined by the other
+options related to buffer contents. The setting can be any pattern of bytes,
+and can be prefixed with 0x for hex values. It may also be a string, where
+the string must then be wrapped with ``""``. Or it may also be a filename,
+where the filename must be wrapped with ``''`` in which case the file is
+opened and read. Note that not all the file contents will be read if that
+would cause the buffers to overflow. So, for example:
+.RS
+.RS
+\fBbuffer_pattern\fR='filename'
+.RS
+or
+.RE
+\fBbuffer_pattern\fR="abcd"
+.RS
+or
+.RE
+\fBbuffer_pattern\fR=-12
+.RS
+or
+.RE
+\fBbuffer_pattern\fR=0xdeadface
+.RE
+.LP
+Also you can combine everything together in any order:
+.LP
+.RS
+\fBbuffer_pattern\fR=0xdeadface"abcd"-12'filename'
+.RE
+.RE
+.TP
+.BI dedupe_percentage \fR=\fPint
+If set, fio will generate this percentage of identical buffers when writing.
+These buffers will be naturally dedupable. The contents of the buffers depend
+on what other buffer compression settings have been set. It's possible to have
+the individual buffers either fully compressible, or not at all. This option
+only controls the distribution of unique buffers.
+.TP
.BI nrfiles \fR=\fPint
Number of files to use for this job. Default: 1.
.TP
.RS
.TP
.B random
-Choose a file at random
+Choose a file at random.
.TP
.B roundrobin
-Round robin over open files (default).
+Round robin over opened files (default).
+.TP
.B sequential
Do each file in the set sequentially.
+.TP
+.B zipf
+Use a zipfian distribution to decide what file to access.
+.TP
+.B pareto
+Use a pareto distribution to decide what file to access.
+.TP
+.B normal
+Use a Gaussian (normal) distribution to decide what file to access.
+.TP
+.B gauss
+Alias for normal.
.RE
.P
-The number of I/Os to issue before switching a new file can be specified by
-appending `:\fIint\fR' to the service type.
+For \fBrandom\fR, \fBroundrobin\fR, and \fBsequential\fR, a postfix can be
+appended to tell fio how many I/Os to issue before switching to a new file.
+For example, specifying \fBfile_service_type=random:8\fR would cause fio to
+issue \fI8\fR I/Os before selecting a new file at random. For the non-uniform
+distributions, a floating point postfix can be given to influence how the
+distribution is skewed. See \fBrandom_distribution\fR for a description of how
+that would work.
.RE
.TP
.BI ioengine \fR=\fPstr
.RS
.TP
.B sync
-Basic \fIread\fR\|(2) or \fIwrite\fR\|(2) I/O. \fIfseek\fR\|(2) is used to
+Basic \fBread\fR\|(2) or \fBwrite\fR\|(2) I/O. \fBfseek\fR\|(2) is used to
position the I/O location.
.TP
.B psync
-Basic \fIpread\fR\|(2) or \fIpwrite\fR\|(2) I/O.
+Basic \fBpread\fR\|(2) or \fBpwrite\fR\|(2) I/O.
+Default on all supported operating systems except for Windows.
.TP
.B vsync
-Basic \fIreadv\fR\|(2) or \fIwritev\fR\|(2) I/O. Will emulate queuing by
-coalescing adjacents IOs into a single submission.
+Basic \fBreadv\fR\|(2) or \fBwritev\fR\|(2) I/O. Will emulate queuing by
+coalescing adjacent IOs into a single submission.
+.TP
+.B pvsync
+Basic \fBpreadv\fR\|(2) or \fBpwritev\fR\|(2) I/O.
+.TP
+.B pvsync2
+Basic \fBpreadv2\fR\|(2) or \fBpwritev2\fR\|(2) I/O.
.TP
.B libaio
Linux native asynchronous I/O. This ioengine defines engine specific options.
.TP
.B posixaio
-POSIX asynchronous I/O using \fIaio_read\fR\|(3) and \fIaio_write\fR\|(3).
+POSIX asynchronous I/O using \fBaio_read\fR\|(3) and \fBaio_write\fR\|(3).
.TP
.B solarisaio
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 \fImmap\fR\|(2) and data copied using
-\fImemcpy\fR\|(3).
+File is memory mapped with \fBmmap\fR\|(2) and data copied using
+\fBmemcpy\fR\|(3).
.TP
.B splice
-\fIsplice\fR\|(2) is used to transfer the data and \fIvmsplice\fR\|(2) to
+\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 \fIread\fR\|(2) and
-\fIwrite\fR\|(2) for asynchronous I/O.
+the target is an sg character device, we use \fBread\fR\|(2) and
+\fBwrite\fR\|(2) for asynchronous I/O.
.TP
.B null
Doesn't transfer any data, just pretends to. Mainly used to exercise \fBfio\fR
This ioengine defines engine specific options.
.TP
.B netsplice
-Like \fBnet\fR, but uses \fIsplice\fR\|(2) and \fIvmsplice\fR\|(2) to map data
+Like \fBnet\fR, but uses \fBsplice\fR\|(2) and \fBvmsplice\fR\|(2) to map data
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
-approach to asycnronous I/O.
+approach to asynchronous I/O.
.br
See <http://www.xmailserver.org/guasi\-lib.html>.
.TP
`:\fIenginepath\fR'.
.TP
.B falloc
- IO engine that does regular linux native fallocate callt to simulate data
+ IO engine that does regular linux native fallocate call to simulate data
transfer as fio ioengine
.br
DDIR_READ does fallocate(,mode = FALLOC_FL_KEEP_SIZE,)
.B e4defrag
IO engine that does regular EXT4_IOC_MOVE_EXT ioctls to simulate defragment activity
request to DDIR_WRITE event
+.TP
+.B rbd
+IO engine supporting direct access to Ceph Rados Block Devices (RBD) via librbd
+without the need to use the kernel rbd driver. This ioengine defines engine specific
+options.
+.TP
+.B gfapi
+Using Glusterfs libgfapi sync interface to direct access to Glusterfs volumes without
+having to go through FUSE. This ioengine defines engine specific
+options.
+.TP
+.B gfapi_async
+Using Glusterfs libgfapi async interface to direct access to Glusterfs volumes without
+having to go through FUSE. This ioengine defines engine specific
+options.
+.TP
+.B libhdfs
+Read and write through Hadoop (HDFS). The \fBfilename\fR option is used to
+specify host,port of the hdfs name-node to connect. This engine interprets
+offsets a little differently. In HDFS, files once created cannot be modified.
+So random writes are not possible. To imitate this, libhdfs engine expects
+bunch of small files to be created over HDFS, and engine will randomly pick a
+file out of those files based on the offset generated by fio backend. (see the
+example job file to create such files, use rw=write option). Please note, you
+might want to set necessary environment variables to work with hdfs/libhdfs
+properly.
+.TP
+.B mtd
+Read, write and erase an MTD character device (e.g., /dev/mtd0). Discards are
+treated as erases. Depending on the underlying device type, the I/O may have
+to go in a certain pattern, e.g., on NAND, writing sequentially to erase blocks
+and discarding before overwriting. The trimwrite mode works well for this
+constraint.
+.TP
+.B pmemblk
+Read and write using filesystem DAX to a file on a filesystem mounted with
+DAX on a persistent memory device through the NVML libpmemblk library.
+.TP
+.B dev-dax
+Read and write using device DAX to a persistent memory device
+(e.g., /dev/dax0.0) through the NVML libpmem library.
.RE
.P
.RE
.BI iodepth \fR=\fPint
Number of I/O units to keep in flight against the file. Note that increasing
iodepth beyond 1 will not affect synchronous ioengines (except for small
-degress when verify_async is in use). Even async engines my impose OS
+degress when verify_async is in use). Even async engines may impose OS
restrictions causing the desired depth not to be achieved. This may happen on
Linux when using libaio and not setting \fBdirect\fR=1, since buffered IO is
not async on that OS. Keep an eye on the IO depth distribution in the
fio output to verify that the achieved depth is as expected. Default: 1.
.TP
-.BI iodepth_batch \fR=\fPint
-Number of I/Os to submit at once. Default: \fBiodepth\fR.
+.BI iodepth_batch \fR=\fPint "\fR,\fP iodepth_batch_submit" \fR=\fPint
+This defines how many pieces of IO to submit at once. It defaults to 1
+which means that we submit each IO as soon as it is available, but can
+be raised to submit bigger batches of IO at the time. If it is set to 0
+the \fBiodepth\fR value will be used.
.TP
-.BI iodepth_batch_complete \fR=\fPint
+.BI iodepth_batch_complete_min \fR=\fPint "\fR,\fP iodepth_batch_complete" \fR=\fPint
This defines how many pieces of IO to retrieve at once. It defaults to 1 which
means that we'll ask for a minimum of 1 IO in the retrieval process from the
kernel. The IO retrieval will go on until we hit the limit set by
completed events before queuing more IO. This helps reduce IO latency, at the
cost of more retrieval system calls.
.TP
+.BI iodepth_batch_complete_max \fR=\fPint
+This defines maximum pieces of IO to
+retrieve at once. This variable should be used along with
+\fBiodepth_batch_complete_min\fR=int variable, specifying the range
+of min and max amount of IO which should be retrieved. By default
+it is equal to \fBiodepth_batch_complete_min\fR value.
+
+Example #1:
+.RS
+.RS
+\fBiodepth_batch_complete_min\fR=1
+.LP
+\fBiodepth_batch_complete_max\fR=<iodepth>
+.RE
+
+which means that we will retrieve at least 1 IO and up to the
+whole submitted queue depth. If none of IO has been completed
+yet, we will wait.
+
+Example #2:
+.RS
+\fBiodepth_batch_complete_min\fR=0
+.LP
+\fBiodepth_batch_complete_max\fR=<iodepth>
+.RE
+
+which means that we can retrieve up to the whole submitted
+queue depth, but if none of IO has been completed yet, we will
+NOT wait and immediately exit the system call. In this example
+we simply do polling.
+.RE
+.TP
.BI iodepth_low \fR=\fPint
Low watermark indicating when to start filling the queue again. Default:
-\fBiodepth\fR.
+\fBiodepth\fR.
+.TP
+.BI io_submit_mode \fR=\fPstr
+This option controls how fio submits the IO to the IO engine. The default is
+\fBinline\fR, which means that the fio job threads submit and reap IO directly.
+If set to \fBoffload\fR, the job threads will offload IO submission to a
+dedicated pool of IO threads. This requires some coordination and thus has a
+bit of extra overhead, especially for lower queue depth IO where it can
+increase latencies. The benefit is that fio can manage submission rates
+independently of the device completion rates. This avoids skewed latency
+reporting if IO gets back up on the device side (the coordinated omission
+problem).
.TP
.BI direct \fR=\fPbool
If true, use non-buffered I/O (usually O_DIRECT). Default: false.
.TP
+.BI atomic \fR=\fPbool
+If value is true, attempt to use atomic direct IO. Atomic writes are guaranteed
+to be stable once acknowledged by the operating system. Only Linux supports
+O_ATOMIC right now.
+.TP
.BI buffered \fR=\fPbool
If true, use buffered I/O. This is the opposite of the \fBdirect\fR parameter.
Default: true.
.TP
.BI offset \fR=\fPint
-Offset in the file to start I/O. Data before the offset will not be touched.
+Start I/O at the provided offset in the file, given as either a fixed size in
+bytes or a percentage. If a percentage is given, the next \fBblockalign\fR-ed
+offset will be used. Data before the given offset will not be touched. This
+effectively caps the file size at (real_size - offset). Can be combined with
+\fBsize\fR to constrain the start and end range of the I/O workload. A percentage
+can be specified by a number between 1 and 100 followed by '%', for example,
+offset=20% to specify 20%.
.TP
.BI offset_increment \fR=\fPint
If this is provided, then the real offset becomes the
-offset + offset_increment * thread_number, where the thread number is a counter
-that starts at 0 and is incremented for each job. This option is useful if
-there are several jobs which are intended to operate on a file in parallel in
-disjoint segments, with even spacing between the starting points.
+offset + offset_increment * thread_number, where the thread number is a
+counter that starts at 0 and is incremented for each sub-job (i.e. when
+numjobs option is specified). This option is useful if there are several jobs
+which are intended to operate on a file in parallel disjoint segments, with
+even spacing between the starting points.
+.TP
+.BI number_ios \fR=\fPint
+Fio will normally perform IOs until it has exhausted the size of the region
+set by \fBsize\fR, or if it exhaust the allocated time (or hits an error
+condition). With this setting, the range/size can be set independently of
+the number of IOs to perform. When fio reaches this number, it will exit
+normally and report status. Note that this does not extend the amount
+of IO that will be done, it will only stop fio if this condition is met
+before other end-of-job criteria.
.TP
.BI fsync \fR=\fPint
How many I/Os to perform before issuing an \fBfsync\fR\|(2) of dirty data. If
Like \fBfsync\fR, but uses \fBfdatasync\fR\|(2) instead to only sync the
data parts of the file. Default: 0.
.TP
+.BI write_barrier \fR=\fPint
+Make every Nth write a barrier write.
+.TP
.BI sync_file_range \fR=\fPstr:int
-Use sync_file_range() for every \fRval\fP number of write operations. Fio will
-track range of writes that have happened since the last sync_file_range() call.
+Use \fBsync_file_range\fR\|(2) for every \fRval\fP number of write operations. Fio will
+track range of writes that have happened since the last \fBsync_file_range\fR\|(2) call.
\fRstr\fP can currently be one or more of:
.RS
.TP
.P
So if you do sync_file_range=wait_before,write:8, fio would use
\fBSYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE\fP for every 8 writes.
-Also see the sync_file_range(2) man page. This option is Linux specific.
+Also see the \fBsync_file_range\fR\|(2) man page. This option is Linux specific.
.TP
.BI overwrite \fR=\fPbool
If writing, setup the file first and do overwrites. Default: false.
.B pareto
Pareto distribution
.TP
+.B normal
+Normal (Gaussian) distribution
+.TP
+.B zoned
+Zoned random distribution
+.TP
.RE
-.P
-When using a zipf or pareto distribution, an input value is also needed to
-define the access pattern. For zipf, this is the zipf theta. For pareto,
-it's the pareto power. Fio includes a test program, genzipf, that can be
-used visualize what the given input values will yield in terms of hit rates.
-If you wanted to use zipf with a theta of 1.2, you would use
+When using a \fBzipf\fR or \fBpareto\fR distribution, an input value is also
+needed to define the access pattern. For \fBzipf\fR, this is the zipf theta.
+For \fBpareto\fR, it's the pareto power. Fio includes a test program, genzipf,
+that can be used visualize what the given input values will yield in terms of
+hit rates. If you wanted to use \fBzipf\fR with a theta of 1.2, you would use
random_distribution=zipf:1.2 as the option. If a non-uniform model is used,
-fio will disable use of the random map.
+fio will disable use of the random map. For the \fBnormal\fR distribution, a
+normal (Gaussian) deviation is supplied as a value between 0 and 100.
+.P
+.RS
+For a \fBzoned\fR distribution, fio supports specifying percentages of IO
+access that should fall within what range of the file or device. For example,
+given a criteria of:
+.P
+.RS
+60% of accesses should be to the first 10%
+.RE
+.RS
+30% of accesses should be to the next 20%
+.RE
+.RS
+8% of accesses should be to to the next 30%
+.RE
+.RS
+2% of accesses should be to the next 40%
+.RE
+.P
+we can define that through zoning of the random accesses. For the above
+example, the user would do:
+.P
+.RS
+.B random_distribution=zoned:60/10:30/20:8/30:2/40
+.RE
+.P
+similarly to how \fBbssplit\fR works for setting ranges and percentages of block
+sizes. Like \fBbssplit\fR, it's possible to specify separate zones for reads,
+writes, and trims. If just one set is given, it'll apply to all of them.
+.RE
+.TP
+.BI percentage_random \fR=\fPint[,int][,int]
+For a random workload, set how big a percentage should be random. This defaults
+to 100%, in which case the workload is fully random. It can be set from
+anywhere from 0 to 100. Setting it to 0 would make the workload fully
+sequential. It is possible to set different values for reads, writes, and
+trim. To do so, simply use a comma separated list. See \fBblocksize\fR.
.TP
.B norandommap
Normally \fBfio\fR will cover every block of the file when doing random I/O. If
.B lfsr
Linear feedback shift register generator
.TP
+.B tausworthe64
+Strong 64-bit 2^258 cycle random number generator
+.TP
.RE
.P
Tausworthe is a strong random number generator, but it requires tracking on the
computationally expensive. It's not a true random generator, however, though
for IO purposes it's typically good enough. LFSR only works with single block
sizes, not with workloads that use multiple block sizes. If used with such a
-workload, fio may read or write some blocks multiple times.
+workload, fio may read or write some blocks multiple times. The default
+value is tausworthe, unless the required space exceeds 2^32 blocks. If it does,
+then tausworthe64 is selected automatically.
.TP
.BI nice \fR=\fPint
-Run job with given nice value. See \fInice\fR\|(2).
+Run job with given nice value. See \fBnice\fR\|(2).
.TP
.BI prio \fR=\fPint
Set I/O priority value of this job between 0 (highest) and 7 (lowest). See
-\fIionice\fR\|(1).
+\fBionice\fR\|(1).
.TP
.BI prioclass \fR=\fPint
-Set I/O priority class. See \fIionice\fR\|(1).
+Set I/O priority class. See \fBionice\fR\|(1).
.TP
.BI thinktime \fR=\fPint
Stall job for given number of microseconds between issuing I/Os.
of the time specified by \fBthinktime\fR. Only valid if \fBthinktime\fR is set.
.TP
.BI thinktime_blocks \fR=\fPint
-Number of blocks to issue before waiting \fBthinktime\fR microseconds.
+Only valid if thinktime is set - control how many blocks to issue, before
+waiting \fBthinktime\fR microseconds. If not set, defaults to 1 which will
+make fio wait \fBthinktime\fR microseconds after every block. This
+effectively makes any queue depth setting redundant, since no more than 1 IO
+will be queued before we have to complete it and do our thinktime. In other
+words, this setting effectively caps the queue depth if the latter is larger.
Default: 1.
.TP
-.BI rate \fR=\fPint
+.BI rate \fR=\fPint[,int][,int]
Cap bandwidth used by this job. The number is in bytes/sec, the normal postfix
rules apply. You can use \fBrate\fR=500k to limit reads and writes to 500k each,
-or you can specify read and writes separately. Using \fBrate\fR=1m,500k would
-limit reads to 1MB/sec and writes to 500KB/sec. Capping only reads or writes
+or you can specify reads, write, and trim limits separately.
+Using \fBrate\fR=1m,500k would
+limit reads to 1MiB/sec and writes to 500KiB/sec. Capping only reads or writes
can be done with \fBrate\fR=,500k or \fBrate\fR=500k,. The former will only
-limit writes (to 500KB/sec), the latter will only limit reads.
+limit writes (to 500KiB/sec), the latter will only limit reads.
.TP
-.BI ratemin \fR=\fPint
+.BI rate_min \fR=\fPint[,int][,int]
Tell \fBfio\fR to do whatever it can to maintain at least the given bandwidth.
Failing to meet this requirement will cause the job to exit. The same format
-as \fBrate\fR is used for read vs write separation.
+as \fBrate\fR is used for read vs write vs trim separation.
.TP
-.BI rate_iops \fR=\fPint
+.BI rate_iops \fR=\fPint[,int][,int]
Cap the bandwidth to this number of IOPS. Basically the same as rate, just
specified independently of bandwidth. The same format as \fBrate\fR is used for
-read vs write seperation. If \fBblocksize\fR is a range, the smallest block
+read vs write vs trim separation. If \fBblocksize\fR is a range, the smallest block
size is used as the metric.
.TP
-.BI rate_iops_min \fR=\fPint
+.BI rate_iops_min \fR=\fPint[,int][,int]
If this rate of I/O is not met, the job will exit. The same format as \fBrate\fR
-is used for read vs write seperation.
-.TP
-.BI ratecycle \fR=\fPint
-Average bandwidth for \fBrate\fR and \fBratemin\fR over this number of
+is used for read vs write vs trim separation.
+.TP
+.BI rate_process \fR=\fPstr
+This option controls how fio manages rated IO submissions. The default is
+\fBlinear\fR, which submits IO in a linear fashion with fixed delays between
+IOs that gets adjusted based on IO completion rates. If this is set to
+\fBpoisson\fR, fio will submit IO based on a more real world random request
+flow, known as the Poisson process
+(https://en.wikipedia.org/wiki/Poisson_process). The lambda will be
+10^6 / IOPS for the given workload.
+.TP
+.BI rate_cycle \fR=\fPint
+Average bandwidth for \fBrate\fR and \fBrate_min\fR over this number of
milliseconds. Default: 1000ms.
.TP
+.BI latency_target \fR=\fPint
+If set, fio will attempt to find the max performance point that the given
+workload will run at while maintaining a latency below this target. The
+values is given in microseconds. See \fBlatency_window\fR and
+\fBlatency_percentile\fR.
+.TP
+.BI latency_window \fR=\fPint
+Used with \fBlatency_target\fR to specify the sample window that the job
+is run at varying queue depths to test the performance. The value is given
+in microseconds.
+.TP
+.BI latency_percentile \fR=\fPfloat
+The percentage of IOs that must fall within the criteria specified by
+\fBlatency_target\fR and \fBlatency_window\fR. If not set, this defaults
+to 100.0, meaning that all IOs must be equal or below to the value set
+by \fBlatency_target\fR.
+.TP
.BI max_latency \fR=\fPint
If set, fio will exit the job if it exceeds this maximum latency. It will exit
with an ETIME error.
.BI cpus_allowed \fR=\fPstr
Same as \fBcpumask\fR, but allows a comma-delimited list of CPU numbers.
.TP
+.BI cpus_allowed_policy \fR=\fPstr
+Set the policy of how fio distributes the CPUs specified by \fBcpus_allowed\fR
+or \fBcpumask\fR. Two policies are supported:
+.RS
+.RS
+.TP
+.B shared
+All jobs will share the CPU set specified.
+.TP
+.B split
+Each job will get a unique CPU from the CPU set.
+.RE
+.P
+\fBshared\fR is the default behaviour, if the option isn't specified. If
+\fBsplit\fR is specified, then fio will assign one cpu per job. If not enough
+CPUs are given for the jobs listed, then fio will roundrobin the CPUs in
+the set.
+.RE
+.P
+.TP
.BI numa_cpu_nodes \fR=\fPstr
-Set this job running on spcified NUMA nodes' CPUs. The arguments allow
+Set this job running on specified NUMA nodes' CPUs. The arguments allow
comma delimited list of cpu numbers, A-B ranges, or 'all'.
.TP
.BI numa_mem_policy \fR=\fPstr
Set this job's memory policy and corresponding NUMA nodes. Format of
-the argements:
+the arguments:
.RS
.TP
.B <mode>[:<nodelist>]
allowed. For \fBbind\fR and \fBinterleave\fR, \fBnodelist\fR allows
comma delimited list of numbers, A-B ranges, or 'all'.
.TP
-.BI startdelay \fR=\fPint
-Delay start of job for the specified number of seconds.
+.BI startdelay \fR=\fPirange
+Delay start of job for the specified number of seconds. Supports all time
+suffixes to allow specification of hours, minutes, seconds and
+milliseconds - seconds are the default if a unit is omitted.
+Can be given as a range which causes each thread to choose randomly out of the
+range.
.TP
.BI runtime \fR=\fPint
Terminate processing after the specified number of seconds.
that the \fBramp_time\fR is considered lead in time for a job, thus it will
increase the total runtime if a special timeout or runtime is specified.
.TP
+.BI steadystate \fR=\fPstr:float "\fR,\fP ss" \fR=\fPstr:float
+Define the criterion and limit for assessing steady state performance. The
+first parameter designates the criterion whereas the second parameter sets the
+threshold. When the criterion falls below the threshold for the specified
+duration, the job will stop. For example, iops_slope:0.1% will direct fio
+to terminate the job when the least squares regression slope falls below 0.1%
+of the mean IOPS. If group_reporting is enabled this will apply to all jobs in
+the group. All assessments are carried out using only data from the rolling
+collection window. Threshold limits can be expressed as a fixed value or as a
+percentage of the mean in the collection window. Below are the available steady
+state assessment criteria.
+.RS
+.RS
+.TP
+.B iops
+Collect IOPS data. Stop the job if all individual IOPS measurements are within
+the specified limit of the mean IOPS (e.g., iops:2 means that all individual
+IOPS values must be within 2 of the mean, whereas iops:0.2% means that all
+individual IOPS values must be within 0.2% of the mean IOPS to terminate the
+job).
+.TP
+.B iops_slope
+Collect IOPS data and calculate the least squares regression slope. Stop the
+job if the slope falls below the specified limit.
+.TP
+.B bw
+Collect bandwidth data. Stop the job if all individual bandwidth measurements
+are within the specified limit of the mean bandwidth.
+.TP
+.B bw_slope
+Collect bandwidth data and calculate the least squares regression slope. Stop
+the job if the slope falls below the specified limit.
+.RE
+.RE
+.TP
+.BI steadystate_duration \fR=\fPtime "\fR,\fP ss_dur" \fR=\fPtime
+A rolling window of this duration will be used to judge whether steady state
+has been reached. Data will be collected once per second. The default is 0
+which disables steady state detection.
+.TP
+.BI steadystate_ramp_time \fR=\fPtime "\fR,\fP ss_ramp" \fR=\fPtime
+Allow the job to run for the specified duration before beginning data collection
+for checking the steady state job termination criterion. The default is 0.
+.TP
.BI invalidate \fR=\fPbool
Invalidate buffer-cache for the file prior to starting I/O. Default: true.
.TP
.RS
.TP
.B malloc
-Allocate memory with \fImalloc\fR\|(3).
+Allocate memory with \fBmalloc\fR\|(3). Default memory type.
.TP
.B shm
-Use shared memory buffers allocated through \fIshmget\fR\|(2).
+Use shared memory buffers allocated through \fBshmget\fR\|(2).
.TP
.B shmhuge
Same as \fBshm\fR, but use huge pages as backing.
.TP
.B mmap
-Use \fImmap\fR\|(2) for allocation. Uses anonymous memory unless a filename
+Use \fBmmap\fR\|(2) for allocation. Uses anonymous memory unless a filename
is given after the option in the format `:\fIfile\fR'.
.TP
.B mmaphuge
Same as \fBmmap\fR, but use huge files as backing.
+.TP
+.B mmapshared
+Same as \fBmmap\fR, but use a MMAP_SHARED mapping.
+.TP
+.B cudamalloc
+Use GPU memory as the buffers for GPUDirect RDMA benchmark. The ioengine must be \fBrdma\fR.
.RE
.P
The amount of memory allocated is the maximum allowed \fBblocksize\fR for the
.RE
.TP
.BI iomem_align \fR=\fPint "\fR,\fP mem_align" \fR=\fPint
-This indiciates the memory alignment of the IO memory buffers. Note that the
+This indicates the memory alignment of the IO memory buffers. Note that the
given alignment is applied to the first IO unit buffer, if using \fBiodepth\fR
the alignment of the following buffers are given by the \fBbs\fR used. In
other words, if using a \fBbs\fR that is a multiple of the page sized in the
.TP
.BI hugepage\-size \fR=\fPint
Defines the size of a huge page. Must be at least equal to the system setting.
-Should be a multiple of 1MB. Default: 4MB.
+Should be a multiple of 1MiB. Default: 4MiB.
.TP
.B exitall
Terminate all jobs when one finishes. Default: wait for each job to finish.
.TP
+.B exitall_on_error \fR=\fPbool
+Terminate all jobs if one job finishes in error. Default: wait for each job
+to finish.
+.TP
.BI bwavgtime \fR=\fPint
-Average bandwidth calculations over the given time in milliseconds. Default:
-500ms.
+Average bandwidth calculations over the given time in milliseconds. If the job
+also does bandwidth logging through \fBwrite_bw_log\fR, then the minimum of
+this option and \fBlog_avg_msec\fR will be used. Default: 500ms.
.TP
.BI iopsavgtime \fR=\fPint
-Average IOPS calculations over the given time in milliseconds. Default:
-500ms.
+Average IOPS calculations over the given time in milliseconds. If the job
+also does IOPS logging through \fBwrite_iops_log\fR, then the minimum of
+this option and \fBlog_avg_msec\fR will be used. Default: 500ms.
.TP
.BI create_serialize \fR=\fPbool
If true, serialize file creation for the jobs. Default: true.
.TP
.BI create_fsync \fR=\fPbool
-\fIfsync\fR\|(2) data file after creation. Default: true.
+\fBfsync\fR\|(2) data file after creation. Default: true.
.TP
.BI create_on_open \fR=\fPbool
If true, the files are not created until they are opened for IO by the job.
laid out or updated on disk, only that will be done. The actual job contents
are not executed.
.TP
+.BI allow_file_create \fR=\fPbool
+If true, fio is permitted to create files as part of its workload. This is
+the default behavior. If this option is false, then fio will error out if the
+files it needs to use don't already exist. Default: true.
+.TP
+.BI allow_mounted_write \fR=\fPbool
+If this isn't set, fio will abort jobs that are destructive (eg that write)
+to what appears to be a mounted device or partition. This should help catch
+creating inadvertently destructive tests, not realizing that the test will
+destroy data on the mounted file system. Default: false.
+.TP
.BI pre_read \fR=\fPbool
If this is given, files will be pre-read into memory before starting the given
IO operation. This will also clear the \fR \fBinvalidate\fR flag, since it is
.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.
.TP
+.BI verify_only \fR=\fPbool
+Do not perform the specified workload, only verify data still matches previous
+invocation of this workload. This option allows one to check data multiple
+times at a later date without overwriting it. This option makes sense only for
+workloads that write data, and does not support workloads with the
+\fBtime_based\fR option set.
+.TP
.BI do_verify \fR=\fPbool
Run the verify phase after a write phase. Only valid if \fBverify\fR is set.
Default: true.
.TP
.BI verify \fR=\fPstr
-Method of verifying file contents after each iteration of the job. Allowed
-values are:
+Method of verifying file contents after each iteration of the job. Each
+verification method also implies verification of special header, which is
+written to the beginning of each block. This header also includes meta
+information, like offset of the block, block number, timestamp when block
+was written, etc. \fBverify\fR=str can be combined with \fBverify_pattern\fR=str
+option. The allowed values are:
.RS
.RS
.TP
-.B md5 crc16 crc32 crc32c crc32c-intel crc64 crc7 sha256 sha512 sha1
+.B md5 crc16 crc32 crc32c crc32c-intel crc64 crc7 sha256 sha512 sha1 sha3-224 sha3-256 sha3-384 sha3-512 xxhash
Store appropriate checksum in the header of each block. crc32c-intel is
hardware accelerated SSE4.2 driven, falls back to regular crc32c if
not supported by the system.
.TP
.B meta
-Write extra information about each I/O (timestamp, block number, etc.). The
-block number is verified. See \fBverify_pattern\fR as well.
+This option is deprecated, since now meta information is included in generic
+verification header and meta verification happens by default. For detailed
+information see the description of the \fBverify\fR=str setting. This option
+is kept because of compatibility's sake with old configurations. Do not use it.
+.TP
+.B pattern
+Verify a strict pattern. Normally fio includes a header with some basic
+information and checksumming, but if this option is set, only the
+specific pattern set with \fBverify_pattern\fR is verified.
.TP
.B null
Pretend to verify. Used for testing internals.
be of the newly written data.
.RE
.TP
-.BI verify_sort \fR=\fPbool
+.BI verifysort \fR=\fPbool
If true, written verify blocks are sorted if \fBfio\fR deems it to be faster to
read them back in a sorted manner. Default: true.
.TP
+.BI verifysort_nr \fR=\fPint
+Pre-load and sort verify blocks for a read workload.
+.TP
.BI verify_offset \fR=\fPint
Swap the verification header with data somewhere else in the block before
writing. It is swapped back before verifying.
fio will fill 1/2/3/4 bytes of the buffer at the time(it can be either a
decimal or a hex number). The verify_pattern if larger than a 32-bit quantity
has to be a hex number that starts with either "0x" or "0X". Use with
-\fBverify\fP=meta.
+\fBverify\fP=str. Also, verify_pattern supports %o format, which means that for
+each block offset will be written and then verified back, e.g.:
+.RS
+.RS
+\fBverify_pattern\fR=%o
+.RE
+Or use combination of everything:
+.LP
+.RS
+\fBverify_pattern\fR=0xff%o"abcd"-21
+.RE
+.RE
.TP
.BI verify_fatal \fR=\fPbool
If true, exit the job on the first observed verification failure. Default:
.BI verify_backlog_batch \fR=\fPint
Control how many blocks fio will verify if verify_backlog is set. If not set,
will default to the value of \fBverify_backlog\fR (meaning the entire queue is
-read back and verified). If \fBverify_backlog_batch\fR is less than
-\fBverify_backlog\fR then not all blocks will be verified, if
+read back and verified). If \fBverify_backlog_batch\fR is less than
+\fBverify_backlog\fR then not all blocks will be verified, if
\fBverify_backlog_batch\fR is larger than \fBverify_backlog\fR, some blocks
will be verified more than once.
.TP
+.BI trim_percentage \fR=\fPint
+Number of verify blocks to discard/trim.
+.TP
+.BI trim_verify_zero \fR=\fPbool
+Verify that trim/discarded blocks are returned as zeroes.
+.TP
+.BI trim_backlog \fR=\fPint
+Trim after this number of blocks are written.
+.TP
+.BI trim_backlog_batch \fR=\fPint
+Trim this number of IO blocks.
+.TP
+.BI experimental_verify \fR=\fPbool
+Enable experimental verification.
+.TP
+.BI verify_state_save \fR=\fPbool
+When a job exits during the write phase of a verify workload, save its
+current state. This allows fio to replay up until that point, if the
+verify state is loaded for the verify read phase.
+.TP
+.BI verify_state_load \fR=\fPbool
+If a verify termination trigger was used, fio stores the current write
+state of each thread. This can be used at verification time so that fio
+knows how far it should verify. Without this information, fio will run
+a full verification pass, according to the settings in the job file used.
+.TP
.B stonewall "\fR,\fP wait_for_previous"
Wait for preceding jobs in the job file to exit before starting this one.
\fBstonewall\fR implies \fBnew_group\fR.
Start a new reporting group. If not given, all jobs in a file will be part
of the same reporting group, unless separated by a stonewall.
.TP
+.BI stats \fR=\fPbool
+By default, fio collects and shows final output results for all jobs that run.
+If this option is set to 0, then fio will ignore it in the final stat output.
+.TP
.BI numjobs \fR=\fPint
-Number of clones (processes/threads performing the same workload) of this job.
+Number of clones (processes/threads performing the same workload) of this job.
Default: 1.
.TP
.B group_reporting
.BI zonesize \fR=\fPint
Divide file into zones of the specified size in bytes. See \fBzoneskip\fR.
.TP
+.BI zonerange \fR=\fPint
+Give size of an IO zone. See \fBzoneskip\fR.
+.TP
.BI zoneskip \fR=\fPint
Skip the specified number of bytes when \fBzonesize\fR bytes of data have been
read.
from. Setting \fBreplay_redirect\fR causes all IOPS to be replayed onto the
single specified device regardless of the device it was recorded from.
.TP
+.BI replay_align \fR=\fPint
+Force alignment of IO offsets and lengths in a trace to this power of 2 value.
+.TP
+.BI replay_scale \fR=\fPint
+Scale sector offsets down by this factor when replaying traces.
+.TP
+.BI per_job_logs \fR=\fPbool
+If set, this generates bw/clat/iops log with per file private filenames. If
+not set, jobs with identical names will share the log filename. Default: true.
+.TP
.BI write_bw_log \fR=\fPstr
-If given, write a bandwidth log of the jobs in this job file. Can be used to
-store data of the bandwidth of the jobs in their lifetime. The included
-fio_generate_plots script uses gnuplot to turn these text files into nice
-graphs. See \fBwrite_log_log\fR for behaviour of given filename. For this
-option, the postfix is _bw.log.
+If given, write a bandwidth log for this job. Can be used to store data of the
+bandwidth of the jobs in their lifetime. The included fio_generate_plots script
+uses gnuplot to turn these text files into nice graphs. See \fBwrite_lat_log\fR
+for behaviour of given filename. For this option, the postfix is _bw.x.log,
+where x is the index of the job (1..N, where N is the number of jobs). 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_lat_log \fR=\fPstr
Same as \fBwrite_bw_log\fR, but writes I/O completion latencies. If no
-filename is given with this option, the default filename of "jobname_type.log"
-is used. Even if the filename is given, fio will still append the type of log.
+filename is given with this option, the default filename of
+"jobname_type.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_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.log" is used. Even if the
-filename is given, fio will still append the type of log.
+option, the default filename of "jobname_type.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 log_avg_msec \fR=\fPint
By default, fio will log an entry in the iops, latency, or bw log for every
IO that completes. When writing to the disk log, that can quickly grow to a
very large size. Setting this option makes fio average the each log entry
-over the specified period of time, reducing the resolution of the log.
-Defaults to 0.
+over the specified period of time, reducing the resolution of the log. See
+\fBlog_max_value\fR as well. Defaults to 0, logging all entries.
+.TP
+.BI log_max_value \fR=\fPbool
+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.
+.TP
+.BI log_compression \fR=\fPint
+If this is set, fio will compress the IO logs as it goes, to keep the memory
+footprint lower. When a log reaches the specified size, that chunk is removed
+and compressed in the background. Given that IO logs are fairly highly
+compressible, this yields a nice memory savings for longer runs. The downside
+is that the compression will consume some background CPU cycles, so it may
+impact the run. This, however, is also true if the logging ends up consuming
+most of the system memory. So pick your poison. The IO logs are saved
+normally at the end of a run, by decompressing the chunks and storing them
+in the specified log file. This feature depends on the availability of zlib.
+.TP
+.BI log_compression_cpus \fR=\fPstr
+Define the set of CPUs that are allowed to handle online log compression
+for the IO jobs. This can provide better isolation between performance
+sensitive jobs, and background compression work.
+.TP
+.BI log_store_compressed \fR=\fPbool
+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
+was encountered.
.TP
.BI disable_lat \fR=\fPbool
Disable measurements of total latency numbers. Useful only for cutting
-back the number of calls to gettimeofday, as that does impact performance at
+back the number of calls to \fBgettimeofday\fR\|(2), as that does impact performance at
really high IOPS rates. Note that to really get rid of a large amount of these
calls, this option must be used with disable_slat and disable_bw as well.
.TP
.TP
.BI lockmem \fR=\fPint
Pin the specified amount of memory with \fBmlock\fR\|(2). Can be used to
-simulate a smaller amount of memory.
+simulate a smaller amount of memory. The amount specified is per worker.
.TP
.BI exec_prerun \fR=\fPstr
Before running the job, execute the specified command with \fBsystem\fR\|(3).
+.RS
+Output is redirected in a file called \fBjobname.prerun.txt\fR
+.RE
.TP
.BI exec_postrun \fR=\fPstr
Same as \fBexec_prerun\fR, but the command is executed after the job completes.
+.RS
+Output is redirected in a file called \fBjobname.postrun.txt\fR
+.RE
.TP
.BI ioscheduler \fR=\fPstr
Attempt to switch the device hosting the file to the specified I/O scheduler.
.TP
-.BI cpuload \fR=\fPint
-If the job is a CPU cycle-eater, attempt to use the specified percentage of
-CPU cycles.
-.TP
-.BI cpuchunks \fR=\fPint
-If the job is a CPU cycle-eater, split the load into cycles of the
-given time in milliseconds.
-.TP
.BI disk_util \fR=\fPbool
Generate disk utilization statistics if the platform supports it. Default: true.
.TP
.RS
.TP
.B gettimeofday
-gettimeofday(2)
+\fBgettimeofday\fR\|(2)
.TP
.B clock_gettime
-clock_gettime(2)
+\fBclock_gettime\fR\|(2)
.TP
.B cpu
Internal CPU clock source
means supporting TSC Invariant.
.TP
.BI gtod_reduce \fR=\fPbool
-Enable all of the gettimeofday() reducing options (disable_clat, disable_slat,
+Enable all of the \fBgettimeofday\fR\|(2) reducing options (disable_clat, disable_slat,
disable_bw) plus reduce precision of the timeout somewhat to really shrink the
-gettimeofday() call count. With this option enabled, we only do about 0.4% of
+\fBgettimeofday\fR\|(2) call count. With this option enabled, we only do about 0.4% of
the gtod() calls we would have done if all time keeping was enabled.
.TP
.BI gtod_cpu \fR=\fPint
Sometimes it's cheaper to dedicate a single thread of execution to just getting
the current time. Fio (and databases, for instance) are very intensive on
-gettimeofday() calls. With this option, you can set one CPU aside for doing
+\fBgettimeofday\fR\|(2) calls. With this option, you can set one CPU aside for doing
nothing but logging current time to a shared memory location. Then the other
threads/processes that run IO workloads need only copy that segment, instead of
-entering the kernel with a gettimeofday() call. The CPU set aside for doing
+entering the kernel with a \fBgettimeofday\fR\|(2) call. The CPU set aside for doing
these time calls will be excluded from other uses. Fio will manually clear it
from the CPU mask of other jobs.
.TP
Error may be symbol ('ENOSPC', 'ENOMEM') or an integer.
.br
Example: ignore_error=EAGAIN,ENOSPC:122 .
-.br
-This option will ignore EAGAIN from READ, and ENOSPC and 122(EDQUOT) from WRITE.
+.br
+This option will ignore EAGAIN from READ, and ENOSPC and 122(EDQUOT) from WRITE.
.TP
.BI error_dump \fR=\fPbool
If set dump every error even if it is non fatal, true by default. If disabled
only fatal error will be dumped
.TP
+.BI profile \fR=\fPstr
+Select a specific builtin performance test.
+.TP
.BI cgroup \fR=\fPstr
Add job to this control group. If it doesn't exist, it will be created.
The system must have a mounted cgroup blkio mount point for this to work. If
.BI gid \fR=\fPint
Set group ID, see \fBuid\fR.
.TP
+.BI unit_base \fR=\fPint
+Base unit for reporting. Allowed values are:
+.RS
+.TP
+.B 0
+Use auto-detection (default).
+.TP
+.B 8
+Byte based.
+.TP
+.B 1
+Bit based.
+.RE
+.P
+.TP
.BI flow_id \fR=\fPint
The ID of the flow. If not specified, it defaults to being a global flow. See
\fBflow\fR.
Enable the reporting of percentiles of completion latencies.
.TP
.BI percentile_list \fR=\fPfloat_list
-Overwrite the default list of percentiles for completion
-latencies. Each number is a floating number in the range (0,100], and
-the maximum length of the list is 20. Use ':' to separate the
+Overwrite the default list of percentiles for completion latencies and the
+block error histogram. Each number is a floating number in the range (0,100],
+and the maximum length of the list is 20. Use ':' to separate the
numbers. For example, \-\-percentile_list=99.5:99.9 will cause fio to
report the values of completion latency below which 99.5% and 99.9% of
the observed latencies fell, respectively.
.SS "Ioengine Parameters List"
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, the must come after the ioengine that defines them is selected.
+command line, they must come after the ioengine.
+.TP
+.BI (cpuio)cpuload \fR=\fPint
+Attempt to use the specified percentage of CPU cycles.
+.TP
+.BI (cpuio)cpuchunks \fR=\fPint
+Split the load into cycles of the given time. In microseconds.
+.TP
+.BI (cpuio)exit_on_io_done \fR=\fPbool
+Detect when IO threads are done, then exit.
.TP
.BI (libaio)userspace_reap
Normally, with the libaio engine in use, fio will use
enabled when polling for a minimum of 0 events (eg when
iodepth_batch_complete=0).
.TP
+.BI (pvsync2)hipri
+Set RWF_HIPRI on IO, indicating to the kernel that it's of
+higher priority than normal.
+.TP
.BI (net,netsplice)hostname \fR=\fPstr
The host name or IP address to use for TCP or UDP based IO.
If the job is a TCP listener or UDP reader, the hostname is not
-used and must be omitted.
+used and must be omitted unless it is a valid UDP multicast address.
.TP
.BI (net,netsplice)port \fR=\fPint
-The TCP or UDP port to bind to or connect to.
+The TCP or UDP port to bind to or connect to. If this is used with
+\fBnumjobs\fR to spawn multiple instances of the same job type, then
+this will be the starting port number since fio will use a range of ports.
+.TP
+.BI (net,netsplice)interface \fR=\fPstr
+The IP address of the network interface used to send or receive UDP multicast
+packets.
+.TP
+.BI (net,netsplice)ttl \fR=\fPint
+Time-to-live value for outgoing UDP multicast packets. Default: 1
.TP
.BI (net,netsplice)nodelay \fR=\fPbool
Set TCP_NODELAY on TCP connections.
.B tcp
Transmission control protocol
.TP
+.B tcpv6
+Transmission control protocol V6
+.TP
.B udp
User datagram protocol
.TP
+.B udpv6
+User datagram protocol V6
+.TP
.B unix
UNIX domain socket
.RE
hostname must be omitted if this option is used.
.TP
.BI (net, pingpong) \fR=\fPbool
-Normal a network writer will just continue writing data, and a network reader
-will just consume packages. If pingpong=1 is set, a writer will send its normal
+Normally a network writer will just continue writing data, and a network reader
+will just consume packets. If pingpong=1 is set, a writer will send its normal
payload to the reader, then wait for the reader to send the same payload back.
This allows fio to measure network latencies. The submission and completion
latencies then measure local time spent sending or receiving, and the
completion latency measures how long it took for the other end to receive and
-send back.
+send back. For UDP multicast traffic pingpong=1 should only be set for a single
+reader when multiple readers are listening to the same address.
+.TP
+.BI (net, window_size) \fR=\fPint
+Set the desired socket buffer size for the connection.
+.TP
+.BI (net, mss) \fR=\fPint
+Set the TCP maximum segment size (TCP_MAXSEG).
.TP
.BI (e4defrag,donorname) \fR=\fPstr
File will be used as a block donor (swap extents between files)
.TP
.BI (e4defrag,inplace) \fR=\fPint
-Configure donor file block allocation strategy
+Configure donor file block allocation strategy
.RS
.BI 0(default) :
Preallocate donor's file on init
.TP
.BI 1:
-allocate space immidietly inside defragment event, and free right after event
+allocate space immediately inside defragment event, and free right after event
.RE
.TP
+.BI (rbd)clustername \fR=\fPstr
+Specifies the name of the ceph cluster.
+.TP
+.BI (rbd)rbdname \fR=\fPstr
+Specifies the name of the RBD.
+.TP
+.BI (rbd)pool \fR=\fPstr
+Specifies the name of the Ceph pool containing the RBD.
+.TP
+.BI (rbd)clientname \fR=\fPstr
+Specifies the username (without the 'client.' prefix) used to access the Ceph
+cluster. If the clustername is specified, the clientname shall be the full
+type.id string. If no type. prefix is given, fio will add 'client.' by default.
+.TP
+.BI (mtd)skipbad \fR=\fPbool
+Skip operations against known bad blocks.
.SH OUTPUT
While running, \fBfio\fR will display the status of the created jobs. For
example:
.RS
.P
-Threads: 1: [_r] [24.8% done] [ 13509/ 8334 kb/s] [eta 00h:01m:31s]
+Jobs: 1: [_r] [24.8% done] [ 13509/ 8334 kb/s] [eta 00h:01m:31s]
.RE
.P
The characters in the first set of brackets denote the current status of each
.TP
.B cpu
CPU usage statistics. Includes user and system time, number of context switches
-this thread went through and number of major and minor page faults.
+this thread went through and number of major and minor page faults. The CPU
+utilization numbers are averages for the jobs in that reporting group, while
+the context and fault counters are summed.
.TP
.B IO depths
Distribution of I/O depths. Each depth includes everything less than (or equal)
running, without terminating the job. To do that, send fio the \fBUSR1\fR
signal.
.SH TERSE OUTPUT
-If the \fB\-\-minimal\fR option is given, the results will be printed in a
-semicolon-delimited format suitable for scripted use - a job description
-(if provided) follows on a new line. Note that the first
+If the \fB\-\-minimal\fR / \fB\-\-append-terse\fR options are given, the
+results will be printed/appended in a semicolon-delimited format suitable for
+scripted use.
+A job description (if provided) follows on a new line. Note that the first
number in the line is the version number. If the output has to be changed
for some reason, this number will be incremented by 1 to signify that
-change. The fields are:
+change. Numbers in brackets (e.g. "[v3]") indicate which terse version
+introduced a field. The fields are:
.P
.RS
-.B terse version, fio version, jobname, groupid, error
+.B terse version, fio version [v3], jobname, groupid, error
.P
Read status:
.RS
-.B Total I/O \fR(KB)\fP, bandwidth \fR(KB/s)\fP, IOPS, runtime \fR(ms)\fP
+.B Total I/O \fR(KiB)\fP, bandwidth \fR(KiB/s)\fP, IOPS, runtime \fR(ms)\fP
.P
Submission latency:
.RS
.RE
Bandwidth:
.RS
-.B min, max, aggregate percentage of total, mean, standard deviation
+.B min, max, aggregate percentage of total, mean, standard deviation, number of samples [v5]
+.RE
+IOPS [v5]:
+.RS
+.B min, max, mean, standard deviation, number of samples
.RE
.RE
.P
Write status:
.RS
-.B Total I/O \fR(KB)\fP, bandwidth \fR(KB/s)\fP, IOPS, runtime \fR(ms)\fP
+.B Total I/O \fR(KiB)\fP, bandwidth \fR(KiB/s)\fP, IOPS, runtime \fR(ms)\fP
.P
Submission latency:
.RS
.RE
Bandwidth:
.RS
-.B min, max, aggregate percentage of total, mean, standard deviation
+.B min, max, aggregate percentage of total, mean, standard deviation, number of samples [v5]
+.RE
+IOPS [v5]:
+.RS
+.B min, max, mean, standard deviation, number of samples
+.RE
.RE
+.P
+Trim status [all but version 3]:
+.RS
+Similar to Read/Write status but for trims.
.RE
.P
CPU usage:
.RE
.RE
.P
-Disk utilization (1 for each disk used):
+Disk utilization (1 for each disk used) [v3]:
.RS
.B name, read ios, write ios, read merges, write merges, read ticks, write ticks, read in-queue time, write in-queue time, disk utilization percentage
.RE
.P
Error Info (dependent on continue_on_error, default off):
.RS
-.B total # errors, first error code
+.B total # errors, first error code
.RE
.P
.B text description (if provided in config - appears on newline)
.RE
+.P
+Below is a single line containing short names for each of the fields in
+the minimal output v3, separated by semicolons:
+.RS
+.P
+.nf
+terse_version_3;fio_version;jobname;groupid;error;read_kb;read_bandwidth;read_iops;read_runtime_ms;read_slat_min;read_slat_max;read_slat_mean;read_slat_dev;read_clat_max;read_clat_min;read_clat_mean;read_clat_dev;read_clat_pct01;read_clat_pct02;read_clat_pct03;read_clat_pct04;read_clat_pct05;read_clat_pct06;read_clat_pct07;read_clat_pct08;read_clat_pct09;read_clat_pct10;read_clat_pct11;read_clat_pct12;read_clat_pct13;read_clat_pct14;read_clat_pct15;read_clat_pct16;read_clat_pct17;read_clat_pct18;read_clat_pct19;read_clat_pct20;read_tlat_min;read_lat_max;read_lat_mean;read_lat_dev;read_bw_min;read_bw_max;read_bw_agg_pct;read_bw_mean;read_bw_dev;write_kb;write_bandwidth;write_iops;write_runtime_ms;write_slat_min;write_slat_max;write_slat_mean;write_slat_dev;write_clat_max;write_clat_min;write_clat_mean;write_clat_dev;write_clat_pct01;write_clat_pct02;write_clat_pct03;write_clat_pct04;write_clat_pct05;write_clat_pct06;write_clat_pct07;write_clat_pct08;write_clat_pct09;write_clat_pct10;write_clat_pct11;write_clat_pct12;write_clat_pct13;write_clat_pct14;write_clat_pct15;write_clat_pct16;write_clat_pct17;write_clat_pct18;write_clat_pct19;write_clat_pct20;write_tlat_min;write_lat_max;write_lat_mean;write_lat_dev;write_bw_min;write_bw_max;write_bw_agg_pct;write_bw_mean;write_bw_dev;cpu_user;cpu_sys;cpu_csw;cpu_mjf;pu_minf;iodepth_1;iodepth_2;iodepth_4;iodepth_8;iodepth_16;iodepth_32;iodepth_64;lat_2us;lat_4us;lat_10us;lat_20us;lat_50us;lat_100us;lat_250us;lat_500us;lat_750us;lat_1000us;lat_2ms;lat_4ms;lat_10ms;lat_20ms;lat_50ms;lat_100ms;lat_250ms;lat_500ms;lat_750ms;lat_1000ms;lat_2000ms;lat_over_2000ms;disk_name;disk_read_iops;disk_write_iops;disk_read_merges;disk_write_merges;disk_read_ticks;write_ticks;disk_queue_time;disk_util
+.fi
+.RE
+.SH TRACE FILE FORMAT
+There are two trace file format that you can encounter. The older (v1) format
+is unsupported since version 1.20-rc3 (March 2008). It will still be described
+below in case that you get an old trace and want to understand it.
+
+In any case the trace is a simple text file with a single action per line.
+
+.P
+.B Trace file format v1
+.RS
+Each line represents a single io action in the following format:
+
+rw, offset, length
+
+where rw=0/1 for read/write, and the offset and length entries being in bytes.
+
+This format is not supported in Fio versions => 1.20-rc3.
+
+.RE
+.P
+.B Trace file format v2
+.RS
+The second version of the trace file format was added in Fio version 1.17.
+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:
+
+\fBfio version 2 iolog\fR
+
+Following this can be lines in two different formats, which are described below.
+The file management format:
+
+\fBfilename action\fR
+
+The filename is given as an absolute path. The action can be one of these:
+
+.P
+.PD 0
+.RS
+.TP
+.B add
+Add the given filename to the trace
+.TP
+.B open
+Open the file with the given filename. The filename has to have been previously
+added with the \fBadd\fR action.
+.TP
+.B close
+Close the file with the given filename. The file must have previously been
+opened.
+.RE
+.PD
+.P
+
+The file io action format:
+
+\fBfilename action offset length\fR
+
+The filename is given as an absolute path, and has to have been added and opened
+before it can be used with this format. The offset and length are given in
+bytes. The action can be one of these:
+
+.P
+.PD 0
+.RS
+.TP
+.B wait
+Wait for 'offset' microseconds. Everything below 100 is discarded. The time is
+relative to the previous wait statement.
+.TP
+.B read
+Read \fBlength\fR bytes beginning from \fBoffset\fR
+.TP
+.B write
+Write \fBlength\fR bytes beginning from \fBoffset\fR
+.TP
+.B sync
+fsync() the file
+.TP
+.B datasync
+fdatasync() the file
+.TP
+.B trim
+trim the given file from the given \fBoffset\fR for \fBlength\fR bytes
+.RE
+.PD
+.P
+
+.SH CPU IDLENESS PROFILING
+In some cases, we want to understand CPU overhead in a test. For example,
+we test patches for the specific goodness of whether they reduce CPU usage.
+fio implements a balloon approach to create a thread per CPU that runs at
+idle priority, meaning that it only runs when nobody else needs the cpu.
+By measuring the amount of work completed by the thread, idleness of each
+CPU can be derived accordingly.
+
+An unit work is defined as touching a full page of unsigned characters. Mean
+and standard deviation of time to complete an unit work is reported in "unit
+work" section. Options can be chosen to report detailed percpu idleness or
+overall system idleness by aggregating percpu stats.
+
+.SH VERIFICATION AND TRIGGERS
+Fio is usually run in one of two ways, when data verification is done. The
+first is a normal write job of some sort with verify enabled. When the
+write phase has completed, fio switches to reads and verifies everything
+it wrote. The second model is running just the write phase, and then later
+on running the same job (but with reads instead of writes) to repeat the
+same IO patterns and verify the contents. Both of these methods depend
+on the write phase being completed, as fio otherwise has no idea how much
+data was written.
+
+With verification triggers, fio supports dumping the current write state
+to local files. Then a subsequent read verify workload can load this state
+and know exactly where to stop. This is useful for testing cases where
+power is cut to a server in a managed fashion, for instance.
+
+A verification trigger consists of two things:
+
+.RS
+Storing the write state of each job
+.LP
+Executing a trigger command
+.RE
+
+The write state is relatively small, on the order of hundreds of bytes
+to single kilobytes. It contains information on the number of completions
+done, the last X completions, etc.
+
+A trigger is invoked either through creation (\fBtouch\fR) of a specified
+file in the system, or through a timeout setting. If fio is run with
+\fB\-\-trigger\-file=/tmp/trigger-file\fR, then it will continually check for
+the existence of /tmp/trigger-file. When it sees this file, it will
+fire off the trigger (thus saving state, and executing the trigger
+command).
+
+For client/server runs, there's both a local and remote trigger. If
+fio is running as a server backend, it will send the job states back
+to the client for safe storage, then execute the remote trigger, if
+specified. If a local trigger is specified, the server will still send
+back the write state, but the client will then execute the trigger.
+
+.RE
+.P
+.B Verification trigger example
+.RS
+
+Lets say we want to run a powercut test on the remote machine 'server'.
+Our write workload is in write-test.fio. We want to cut power to 'server'
+at some point during the run, and we'll run this test from the safety
+or our local machine, 'localbox'. On the server, we'll start the fio
+backend normally:
+
+server# \fBfio \-\-server\fR
+
+and on the client, we'll fire off the workload:
+
+localbox$ \fBfio \-\-client=server \-\-trigger\-file=/tmp/my\-trigger \-\-trigger-remote="bash \-c "echo b > /proc/sysrq-triger""\fR
+
+We set \fB/tmp/my-trigger\fR as the trigger file, and we tell fio to execute
+
+\fBecho b > /proc/sysrq-trigger\fR
+
+on the server once it has received the trigger and sent us the write
+state. This will work, but it's not \fIreally\fR cutting power to the server,
+it's merely abruptly rebooting it. If we have a remote way of cutting
+power to the server through IPMI or similar, we could do that through
+a local trigger command instead. Lets assume we have a script that does
+IPMI reboot of a given hostname, ipmi-reboot. On localbox, we could
+then have run fio with a local trigger instead:
+
+localbox$ \fBfio \-\-client=server \-\-trigger\-file=/tmp/my\-trigger \-\-trigger="ipmi-reboot server"\fR
+
+For this case, fio would wait for the server to send us the write state,
+then execute 'ipmi-reboot server' when that happened.
+
+.RE
+.P
+.B Loading verify state
+.RS
+To load store write state, read verification job file must contain
+the verify_state_load option. If that is set, fio will load the previously
+stored state. For a local fio run this is done by loading the files directly,
+and on a client/server run, the server backend will ask the client to send
+the files over and load them from there.
+
+.RE
+
+.SH LOG FILE FORMATS
+
+Fio supports a variety of log file formats, for logging latencies, bandwidth,
+and IOPS. The logs share a common format, which looks like this:
+
+.B time (msec), value, data direction, offset
+
+Time for the log entry is always in milliseconds. The value logged depends
+on the type of log, it will be one of the following:
+
+.P
+.PD 0
+.TP
+.B Latency log
+Value is in latency in usecs
+.TP
+.B Bandwidth log
+Value is in KiB/sec
+.TP
+.B IOPS log
+Value is in IOPS
+.PD
+.P
+
+Data direction is one of the following:
+
+.P
+.PD 0
+.TP
+.B 0
+IO is a READ
+.TP
+.B 1
+IO is a WRITE
+.TP
+.B 2
+IO is a TRIM
+.PD
+.P
+
+The \fIoffset\fR is the offset, in bytes, from the start of the file, for that
+particular IO. The logging of the offset can be toggled with \fBlog_offset\fR.
+
+If windowed logging is enabled through \fBlog_avg_msec\fR, then fio doesn't log
+individual IOs. Instead of logs the average values over the specified
+period of time. Since \fIdata direction\fR and \fIoffset\fR are per-IO values,
+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
Normally you would run fio as a stand-alone application on the machine
where the IO workload should be generated. However, it is also possible to
socket. 'hostname' is either a hostname or IP address, and 'port' is the port to
listen to (only valid for TCP/IP, not a local socket). Some examples:
-1) fio \-\-server
+1) \fBfio \-\-server\fR
Start a fio server, listening on all interfaces on the default port (8765).
-2) fio \-\-server=ip:hostname,4444
+2) \fBfio \-\-server=ip:hostname,4444\fR
Start a fio server, listening on IP belonging to hostname and on port 4444.
-3) fio \-\-server=ip6:::1,4444
+3) \fBfio \-\-server=ip6:::1,4444\fR
Start a fio server, listening on IPv6 localhost ::1 and on port 4444.
-4) fio \-\-server=,4444
+4) \fBfio \-\-server=,4444\fR
Start a fio server, listening on all interfaces on port 4444.
-5) fio \-\-server=1.2.3.4
+5) \fBfio \-\-server=1.2.3.4\fR
Start a fio server, listening on IP 1.2.3.4 on the default port.
-6) fio \-\-server=sock:/tmp/fio.sock
+6) \fBfio \-\-server=sock:/tmp/fio.sock\fR
Start a fio server, listening on the local socket /tmp/fio.sock.
When a server is running, you can connect to it from a client. The client
is run with:
-fio \-\-local-args \-\-client=server \-\-remote-args <job file(s)>
+\fBfio \-\-local-args \-\-client=server \-\-remote-args <job file(s)>\fR
where \-\-local-args are arguments that are local to the client where it is
running, 'server' is the connect string, and \-\-remote-args and <job file(s)>
does on the server side, to allow IP/hostname/socket and port strings.
You can connect to multiple clients as well, to do that you could run:
-fio \-\-client=server2 \-\-client=server2 <job file(s)>
+\fBfio \-\-client=server2 \-\-client=server2 <job file(s)>\fR
+
+If the job file is located on the fio server, then you can tell the server
+to load a local file as well. This is done by using \-\-remote-config:
+
+\fBfio \-\-client=server \-\-remote-config /path/to/file.fio\fR
+
+Then fio will open this local (to the server) job file instead
+of being passed one from the client.
+
+If you have many servers (example: 100 VMs/containers), you can input a pathname
+of a file containing host IPs/names as the parameter value for the \-\-client option.
+For example, here is an example "host.list" file containing 2 hostnames:
+
+host1.your.dns.domain
+.br
+host2.your.dns.domain
+
+The fio command would then be:
+
+\fBfio \-\-client=host.list <job file>\fR
+
+In this mode, you cannot input server-specific parameters or job files, and all
+servers receive the same job file.
+
+In order to enable fio \-\-client runs utilizing a shared filesystem from multiple hosts,
+fio \-\-client now prepends the IP address of the server to the filename. For example,
+if fio is using directory /mnt/nfs/fio and is writing filename fileio.tmp,
+with a \-\-client hostfile
+containing two hostnames h1 and h2 with IP addresses 192.168.10.120 and 192.168.10.121, then
+fio will create two files:
+
+/mnt/nfs/fio/192.168.10.120.fileio.tmp
+.br
+/mnt/nfs/fio/192.168.10.121.fileio.tmp
+
.SH AUTHORS
.B fio
was written by Jens Axboe <jens.axboe@oracle.com>,
-now Jens Axboe <jaxboe@fusionio.com>.
+now Jens Axboe <axboe@fb.com>.
.br
This man page was written by Aaron Carroll <aaronc@cse.unsw.edu.au> based
on documentation by Jens Axboe.
For further documentation see \fBHOWTO\fR and \fBREADME\fR.
.br
Sample jobfiles are available in the \fBexamples\fR directory.
+.br
+These are typically located under /usr/share/doc/fio.
+\fBHOWTO\fR: http://git.kernel.dk/cgit/fio/plain/HOWTO
+.br
+\fBREADME\fR: http://git.kernel.dk/cgit/fio/plain/README
+.br
projects / fio.git / blobdiff