-.TH fio 1 "September 2007" "User Manual"
+.TH fio 1 "October 2013" "User Manual"
.SH NAME
fio \- flexible I/O tester
.SH SYNOPSIS
.B \-\-minimal
Print statistics in a terse, semicolon-delimited format.
.TP
+.B \-\-append-terse
+Print statistics in selected mode AND terse, semicolon-delimited format.
+.TP
.B \-\-version
Display version information and exit.
.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
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.
+respectively. 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.
+When specifying times the default suffix meaning changes, still denoting the
+base unit of the value, but accepted suffixes are 'D' (days), 'H' (hours), 'M'
+(minutes), 'S' Seconds, 'ms' (or msec) milli seconds, 'us' (or 'usec') micro
+seconds. Time values without a unit specify seconds.
+The suffixes are not case sensitive.
.TP
.I bool
Boolean: a true or false value. `0' denotes false, `1' denotes true.
.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.
.TP
.BI filename \fR=\fPstr
.B fio
set, the fio will sum the results and report 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 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 use_os_rand \fR=\fPbool
Fio can either use the random generator supplied by the OS to generator random
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'.
.RE
.TP
.BI fadvise_hint \fR=\fPbool
-Use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
+Use of \fBposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
are likely to be issued. Default: true.
.TP
.BI size \fR=\fPint
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 io buffers with this pattern. If not set, the contents
+of io buffers is 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.
+.TP
.BI nrfiles \fR=\fPint
Number of files to use for this job. Default: 1.
.TP
.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.
.TP
.B vsync
-Basic \fIreadv\fR\|(2) or \fIwritev\fR\|(2) I/O. Will emulate queuing by
+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 \fIpreadv\fR\|(2) or \fIpwritev\fR\|(2) I/O.
+Basic \fBpreadv\fR\|(2) or \fBpwritev\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.
Windows native asynchronous I/O.
.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
.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
.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.
.RE
.P
.RE
.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.
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.
workload, fio may read or write some blocks multiple times.
.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.
Average bandwidth for \fBrate\fR and \fBratemin\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 specified NUMA nodes' CPUs. The arguments allow
comma delimited list of cpu numbers, A-B ranges, or 'all'.
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 ommited.
+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.
.RS
.TP
.B malloc
-Allocate memory with \fImalloc\fR\|(3).
+Allocate memory with \fBmalloc\fR\|(3).
.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
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.
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.
.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 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
.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
.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
.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
allocate space immediately inside defragment event, and free right after event
.RE
.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.
.SH OUTPUT
While running, \fBfio\fR will display the status of the created jobs. For
example:
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:
projects / fio.git / blobdiff