Specifies when real-time ETA estimate should be printed. \fIwhen\fR may
be one of `always', `never' or `auto'.
.TP
+.BI \-\-section \fR=\fPsec
+Only run section \fIsec\fR from job file.
+.TP
.BI \-\-cmdhelp \fR=\fPcommand
Print help information for \fIcommand\fR. May be `all' for all commands.
.TP
+.BI \-\-debug \fR=\fPtype
+Enable verbose tracing of various fio actions. May be `all' for all types
+or individual types seperated by a comma (eg --debug=io,file). `help' will
+list all available tracing options.
+.TP
.B \-\-help
Display usage information and exit.
.TP
String: a sequence of alphanumeric characters.
.TP
.I int
-Integer: a whole number, possibly negative. If prefixed with `0x', the value
-is assumed to be base 16 (hexadecimal).
-.TP
-.I siint
SI integer: a whole number, possibly containing a suffix denoting the base unit
of the value. Accepted suffixes are `k', 'M' and 'G', denoting kilo (1024),
-mega (1024*1024) and giga (1024*1024*1024) respectively.
+mega (1024*1024) and giga (1024*1024*1024) respectively. If prefixed with '0x',
+the value is assumed to be base 16 (hexadecimal).
.TP
.I bool
Boolean: a true or false value. `0' denotes false, `1' denotes true.
reserved name, meaning stdin or stdout, depending on the read/write direction
set.
.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
+result consistent. This is usual for emulating real workloads that share files.
+The lock modes are:
+.RS
+.RS
+.TP
+.B none
+No locking. This is the default.
+.TP
+.B exclusive
+Only one thread or process may do IO at the 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
+.P
+The option may be post-fixed with a lock batch number. If set, then each
+thread/process may do that amount of IOs to the file before giving up the lock.
+Since lock acquisition is expensive, batching the lock/unlocks will speed up IO.
+.RE
+.P
.BI opendir \fR=\fPstr
Recursively open any files below directory \fIstr\fR.
.TP
Disable use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
are likely to be issued. Default: true.
.TP
-.BI size \fR=\fPsiint
+.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 \fBnr_files\fR and \fBfilesize\fR options are given, this amount will be
divided between the available files for the job.
.TP
+.BI fill_device \fR=\fPbool
+Sets size to something really large and waits for ENOSPC (no space left on
+device) as the terminating condition. Only makes sense with sequential write.
+For a read workload, the mount point will be filled first then IO started on
+the result.
+.TP
.BI filesize \fR=\fPirange
Individual file sizes. May be a range, in which case \fBfio\fR will select sizes
for files at random within the given range, limited to \fBsize\fR in total (if
that is given). If \fBfilesize\fR is not specified, each created file is the
same size.
.TP
-.BI blocksize \fR=\fPsiint "\fR,\fB bs" \fR=\fPsiint
+.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 seperately 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 "\fR,\fB bsrange" \fR=\fPirange
+.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, but can be specified seperately (see \fBblocksize\fR).
+to both reads and writes if only one range is given, but can be specified
+seperately with a comma seperating the values. Example: bsrange=1k-4k,2k-8k.
+Also (see \fBblocksize\fR).
+.TP
+.BI bssplit \fR=\fPstr
+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
+block sizes. The format of the option is bssplit=blocksize/percentage,
+optionally adding as many definitions as needed seperated 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.
.TP
.B blocksize_unaligned\fR,\fP bs_unaligned
If set, any size in \fBblocksize_range\fR may be used. 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.
+.TP
.B zero_buffers
Initialise 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
+default is to only fill it at init time and reuse that data. Only makes sense
+if zero_buffers isn't specified, naturally. If data verification is enabled,
+refill_buffers is also automatically enabled.
+.TP
.BI nrfiles \fR=\fPint
Number of files to use for this job. Default: 1.
.TP
.TP
.B roundrobin
Round robin over open files (default).
+.B sequential
+Do each file in the set sequentially.
.RE
.P
The number of I/Os to issue before switching a new file can be specified by
.B psync
Basic \fIpread\fR\|(2) or \fIpwrite\fR\|(2) I/O.
.TP
+.B vsync
+Basic \fIreadv\fR\|(2) or \fIwritev\fR\|(2) I/O. Will emulate queuing by
+coalescing adjacents IOs into a single submission.
+.TP
.B libaio
Linux native asynchronous I/O.
.TP
.BI iodepth_batch \fR=\fPint
Number of I/Os to submit at once. Default: \fBiodepth\fR.
.TP
+.BI 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
+\fBiodepth_low\fR. If this variable is set to 0, then fio will always check for
+completed events before queuing more IO. This helps reduce IO latency, at the
+cost of more retrieval system calls.
+.TP
.BI iodepth_low \fR=\fPint
Low watermark indicating when to start filling the queue again. Default:
\fBiodepth\fR.
If true, use buffered I/O. This is the opposite of the \fBdirect\fR parameter.
Default: true.
.TP
-.BI offset \fR=\fPsiint
+.BI offset \fR=\fPint
Offset in the file to start I/O. Data before the offset will not be touched.
.TP
.BI fsync \fR=\fPint
How many I/Os to perform before issuing an \fBfsync\fR\|(2) of dirty data. If
0, don't sync. Default: 0.
.TP
+.BI fdatasync \fR=\fPint
+Like \fBfsync\fR, but uses \fBfdatasync\fR\|(2) instead to only sync the
+data parts of the file. Default: 0.
+.TP
.BI overwrite \fR=\fPbool
If writing, setup the file first and do overwrites. Default: false.
.TP
.TP
.BI rwmixwrite \fR=\fPint
Percentage of a mixed workload that should be writes. If \fBrwmixread\fR and
-\fBwrmixwrite\fR are given and do not sum to 100%, the latter of the two
-overrides the first. Default: 50.
+\fBrwmixwrite\fR are given and do not sum to 100%, the latter of the two
+overrides the first. This may interfere with a given rate setting, if fio is
+asked to limit reads or writes to a certain rate. If that is the case, then
+the distribution may be skewed. Default: 50.
.TP
.B norandommap
Normally \fBfio\fR will cover every block of the file when doing random I/O. If
this parameter is given, a new offset will be chosen without looking at past
I/O history. This parameter is mutually exclusive with \fBverify\fR.
.TP
+.B softrandommap
+See \fBnorandommap\fR. If fio runs with the random block map enabled and it
+fails to allocate the map, if this option is set it will continue without a
+random block map. As coverage will not be as complete as with random maps, this
+option is disabled by default.
+.TP
.BI nice \fR=\fPint
Run job with given nice value. See \fInice\fR\|(2).
.TP
Default: 1.
.TP
.BI rate \fR=\fPint
-Cap bandwidth used by this job to this number of KiB/s.
+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
+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.
.TP
.BI ratemin \fR=\fPint
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.
+Failing to meet this requirement will cause the job to exit. The same format
+as \fBrate\fR is used for read vs write separation.
.TP
.BI rate_iops \fR=\fPint
-Cap the bandwidth to this number of IOPS. If \fBblocksize\fR is a range, the
-smallest block size is used as the metric.
+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
+size is used as the metric.
.TP
.BI rate_iops_min \fR=\fPint
-If this rate of I/O is not met, the job will exit.
+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
completely read or written. The same workload will be repeated as many times
as \fBruntime\fR allows.
.TP
+.BI ramp_time \fR=\fPint
+If set, fio will run the specified workload for this amount of time before
+logging any performance numbers. Useful for letting performance settle before
+logging results, thus minimizing the runtime required for stable results. Note
+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 invalidate \fR=\fPbool
Invalidate buffer-cache for the file prior to starting I/O. Default: true.
.TP
have hugetlbfs mounted, and \fIfile\fR must point there.
.RE
.TP
-.BI hugepage\-size \fR=\fPsiint
+.BI iomem_align \fR=\fPint
+This indiciates 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
+system, all buffers will be aligned to this value. If using a \fBbs\fR that
+is not page aligned, the alignment of subsequent IO memory buffers is the
+sum of the \fBiomem_align\fR and \fBbs\fR used.
+.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 1MiB. Default: 4MiB.
.TP
.BI create_fsync \fR=\fPbool
\fIfsync\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.
+.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
+pointless to pre-read and then drop the cache. This will only work for IO
+engines that are seekable, since they allow you to read the same data
+multiple times. Thus it will not work on eg network or splice IO.
+.TP
.BI unlink \fR=\fPbool
Unlink job files when done. Default: false.
.TP
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 verify_offset \fR=\fPsiint
+.BI verify_offset \fR=\fPint
Swap the verification header with data somewhere else in the block before
writing. It is swapped back before verifying.
.TP
-.BI verify_interval \fR=\fPsiint
+.BI verify_interval \fR=\fPint
Write the verification header for this number of bytes, which should divide
\fBblocksize\fR. Default: \fBblocksize\fR.
.TP
If true, exit the job on the first observed verification failure. Default:
false.
.TP
+.BI verify_async \fR=\fPint
+Fio will normally verify IO inline from the submitting thread. This option
+takes an integer describing how many async offload threads to create for IO
+verification instead, causing fio to offload the duty of verifying IO contents
+to one or more separate threads.
+.TP
+.BI verify_async_cpus \fR=\fPstr
+Tell fio to set the given CPU affinity on the async IO verification threads.
+See \fBcpus_allowed\fP for the format used.
+.TP
.B stonewall
Wait for preceeding jobs in the job file to exit before starting this one.
\fBstonewall\fR implies \fBnew_group\fR.
Use threads created with \fBpthread_create\fR\|(3) instead of processes created
with \fBfork\fR\|(2).
.TP
-.BI zonesize \fR=\fPsiint
+.BI zonesize \fR=\fPint
Divide file into zones of the specified size in bytes. See \fBzoneskip\fR.
.TP
-.BI zoneskip \fR=\fPsiint
+.BI zoneskip \fR=\fPint
Skip the specified number of bytes when \fBzonesize\fR bytes of data have been
read.
.TP
Replay the I/O patterns contained in the specified file generated by
\fBwrite_iolog\fR, or may be a \fBblktrace\fR binary file.
.TP
-.B write_bw_log
-If given, write bandwidth logs of the jobs in this file.
+.B 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.
.TP
.B write_lat_log
-Same as \fBwrite_bw_log\fR, but writes I/O completion latencies.
+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.
+.TP
+.B disable_clat \fR=\fPbool
+Disable measurements of completion latency numbers. Useful only for cutting
+back the number of calls to gettimeofday, 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
-.BI lockmem \fR=\fPsiint
+.B disable_slat \fR=\fPbool
+Disable measurements of submission latency numbers. See \fBdisable_clat\fR.
+.TP
+.B disable_bw_measurement \fR=\fPbool
+Disable measurements of throughput/bandwidth numbers. See \fBdisable_clat\fR.
+.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.
.TP
.TP
.BI disk_util \fR=\fPbool
Generate disk utilization statistics if the platform supports it. Default: true.
+.TP
+.BI gtod_reduce \fR=\fPbool
+Enable all of the gettimeofday() 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
+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
+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
+these time calls will be excluded from other uses. Fio will manually clear it
+from the CPU mask of other jobs.
+.TP
+.BI continue_on_error \fR=\fPbool
+Normally fio will exit the job on the first observed failure. If this option is
+set, fio will continue the job when there is a 'non-fatal error'
+(\fBEIO\fR or \fBEILSEQ\fR) until the runtime is exceeded or the I/O size
+specified is completed. If this option is used, there are two more stats that
+are appended, the total error count and the first error. The error field given
+in the stats is the first error that was hit during the run.
.SH OUTPUT
While running, \fBfio\fR will display the status of the created jobs. For
example:
.P
CPU usage:
.RS
-.B user, system, context switches
+.B user, system, context switches, major page faults, minor page faults
.RE
.P
IO depth distribution:
This man page was written by Aaron Carroll <aaronc@cse.unsw.edu.au> based
on documentation by Jens Axboe.
.SH "REPORTING BUGS"
-Report bugs to the \fBfio\fR mailing list <fio-devel@kernel.dk>.
+Report bugs to the \fBfio\fR mailing list <fio@vger.kernel.org>.
See \fBREADME\fR.
.SH "SEE ALSO"
For further documentation see \fBHOWTO\fR and \fBREADME\fR.
projects / fio.git / blobdiff