| .TH fio 1 "September 2007" "User Manual" |
| .SH NAME |
| fio \- flexible I/O tester |
| .SH SYNOPSIS |
| .B fio |
| [\fIoptions\fR] [\fIjobfile\fR]... |
| .SH DESCRIPTION |
| .B fio |
| is a tool that will spawn a number of threads or processes doing a |
| particular type of I/O action as specified by the user. |
| The typical use of fio is to write a job file matching the I/O load |
| one wants to simulate. |
| .SH OPTIONS |
| .TP |
| .BI \-\-output \fR=\fPfilename |
| Write output to \fIfilename\fR. |
| .TP |
| .BI \-\-timeout \fR=\fPtimeout |
| Limit run time to \fItimeout\fR seconds. |
| .TP |
| .B \-\-latency\-log |
| Generate per-job latency logs. |
| .TP |
| .B \-\-bandwidth\-log |
| Generate per-job bandwidth logs. |
| .TP |
| .B \-\-minimal |
| Print statistics in a terse, semicolon-delimited format. |
| .TP |
| .BI \-\-showcmd \fR=\fPjobfile |
| Convert \fIjobfile\fR to a set of command-line options. |
| .TP |
| .B \-\-readonly |
| Enable read-only safety checks. |
| .TP |
| .BI \-\-eta \fR=\fPwhen |
| 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 |
| .B \-\-version |
| Display version information and exit. |
| .SH "JOB FILE FORMAT" |
| Job files are in `ini' format. They consist of one or more |
| job definitions, which begin with a job name in square brackets and |
| extend to the next job name. The job name can be any ASCII string |
| except `global', which has a special meaning. Following the job name is |
| a sequence of zero or more parameters, one per line, that define the |
| behavior of the job. Any line starting with a `;' or `#' character is |
| considered a comment and ignored. |
| .P |
| If \fIjobfile\fR is specified as `-', the job file will be read from |
| standard input. |
| .SS "Global Section" |
| The global section contains default parameters for jobs specified in the |
| job file. A job is only affected by global sections residing above it, |
| and there may be any number of global sections. Specific job definitions |
| may override any parameter set in global sections. |
| .SH "JOB PARAMETERS" |
| .SS Types |
| Some parameters may take arguments of a specific type. The types used are: |
| .TP |
| .I str |
| 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. |
| .TP |
| .I bool |
| Boolean: a true or false value. `0' denotes false, `1' denotes true. |
| .TP |
| .I irange |
| Integer range: a range of integers specified in the format |
| \fIlower\fR:\fIupper\fR or \fIlower\fR\-\fIupper\fR. \fIlower\fR and |
| \fIupper\fR may contain a suffix as described above. If an option allows two |
| sets of ranges, they are separated with a `,' or `/' character. For example: |
| `8\-8k/8M\-4G'. |
| .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 description \fR=\fPstr |
| Human-readable description of the job. It is printed when the job is run, but |
| otherwise has no special purpose. |
| .TP |
| .BI directory \fR=\fPstr |
| Prefix filenames with this directory. Used to place files in a location other |
| than `./'. |
| .TP |
| .BI filename \fR=\fPstr |
| .B fio |
| normally makes up a file name based on the job name, thread number, and file |
| number. If you want to share files between threads in a job or several jobs, |
| specify a \fIfilename\fR for each of them to override the default. If the I/O |
| engine used is `net', \fIfilename\fR is the host and port to connect to in the |
| format \fIhost\fR/\fIport\fR. 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. |
| .TP |
| .BI opendir \fR=\fPstr |
| Recursively open any files below directory \fIstr\fR. |
| .TP |
| .BI readwrite \fR=\fPstr "\fR,\fP rw" \fR=\fPstr |
| Type of I/O pattern. Accepted values are: |
| .RS |
| .RS |
| .TP |
| .B read |
| Sequential reads. |
| .TP |
| .B write |
| Sequential writes. |
| .TP |
| .B randread |
| Random reads. |
| .TP |
| .B randwrite |
| Random writes. |
| .TP |
| .B rw |
| Mixed sequential reads and writes. |
| .TP |
| .B randrw |
| Mixed random reads and writes. |
| .RE |
| .P |
| For mixed I/O, the default split is 50/50. For random I/O, the number of I/Os |
| to perform before getting a new offset can be specified by appending |
| `:\fIint\fR' to the pattern type. The default is 1. |
| .RE |
| .TP |
| .BI randrepeat \fR=\fPbool |
| Seed the random number generator in a predictable way so results are repeatable |
| across runs. Default: true. |
| .TP |
| .BI fadvise_hint \fR=\fPbool |
| 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 |
| 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 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[,siint] "\fR,\fB bs" \fR=\fPsiint[,siint] |
| 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[,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 |
| 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. |
| .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 |
| .B zero_buffers |
| Initialise buffers with all zeros. Default: fill buffers with random data. |
| .TP |
| .BI nrfiles \fR=\fPint |
| Number of files to use for this job. Default: 1. |
| .TP |
| .BI openfiles \fR=\fPint |
| Number of files to keep open at the same time. Default: \fBnrfiles\fR. |
| .TP |
| .BI file_service_type \fR=\fPstr |
| Defines how files to service are selected. The following types are defined: |
| .RS |
| .RS |
| .TP |
| .B random |
| Choose a file at random |
| .TP |
| .B roundrobin |
| Round robin over open files (default). |
| .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. |
| .RE |
| .TP |
| .BI ioengine \fR=\fPstr |
| Defines how the job issues I/O. The following types are defined: |
| .RS |
| .RS |
| .TP |
| .B sync |
| Basic \fIread\fR\|(2) or \fIwrite\fR\|(2) I/O. \fIfseek\fR\|(2) is used to |
| position the I/O location. |
| .TP |
| .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 |
| .B posixaio |
| glibc POSIX asynchronous I/O using \fIaio_read\fR\|(3) and \fIaio_write\fR\|(3). |
| .TP |
| .B mmap |
| File is memory mapped with \fImmap\fR\|(2) and data copied using |
| \fImemcpy\fR\|(3). |
| .TP |
| .B splice |
| \fIsplice\fR\|(2) is used to transfer the data and \fIvmsplice\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. |
| .TP |
| .B null |
| Doesn't transfer any data, just pretends to. Mainly used to exercise \fBfio\fR |
| itself and for debugging and testing purposes. |
| .TP |
| .B net |
| Transfer over the network. \fBfilename\fR must be set appropriately to |
| `\fIhost\fR/\fIport\fR' regardless of data direction. If receiving, only the |
| \fIport\fR argument is used. |
| .TP |
| .B netsplice |
| Like \fBnet\fR, but uses \fIsplice\fR\|(2) and \fIvmsplice\fR\|(2) to map data |
| and send/receive. |
| .TP |
| .B cpuio |
| Doesn't transfer any data, but burns CPU cycles according to \fBcpuload\fR and |
| \fBcpucycles\fR parameters. |
| .TP |
| .B guasi |
| The GUASI I/O engine is the Generic Userspace Asynchronous Syscall Interface |
| approach to asycnronous I/O. |
| .br |
| See <http://www.xmailserver.org/guasi\-lib.html>. |
| .TP |
| .B external |
| Loads an external I/O engine object file. Append the engine filename as |
| `:\fIenginepath\fR'. |
| .RE |
| .RE |
| .TP |
| .BI iodepth \fR=\fPint |
| Number of I/O units to keep in flight against the file. Default: 1. |
| .TP |
| .BI iodepth_batch \fR=\fPint |
| Number of I/Os to submit at once. Default: \fBiodepth\fR. |
| .TP |
| .BI iodepth_low \fR=\fPint |
| Low watermark indicating when to start filling the queue again. Default: |
| \fBiodepth\fR. |
| .TP |
| .BI direct \fR=\fPbool |
| If true, use non-buffered I/O (usually O_DIRECT). Default: false. |
| .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=\fPsiint |
| 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 overwrite \fR=\fPbool |
| If writing, setup the file first and do overwrites. Default: false. |
| .TP |
| .BI end_fsync \fR=\fPbool |
| Sync file contents when job exits. Default: false. |
| .TP |
| .BI fsync_on_close \fR=\fPbool |
| If true, sync file contents on close. This differs from \fBend_fsync\fR in that |
| it will happen on every close, not just at the end of the job. Default: false. |
| .TP |
| .BI rwmixcycle \fR=\fPint |
| How many milliseconds before switching between reads and writes for a mixed |
| workload. Default: 500ms. |
| .TP |
| .BI rwmixread \fR=\fPint |
| Percentage of a mixed workload that should be reads. Default: 50. |
| .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. |
| .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 |
| .BI nice \fR=\fPint |
| Run job with given nice value. See \fInice\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). |
| .TP |
| .BI prioclass \fR=\fPint |
| Set I/O priority class. See \fIionice\fR\|(1). |
| .TP |
| .BI thinktime \fR=\fPint |
| Stall job for given number of microseconds between issuing I/Os. |
| .TP |
| .BI thinktime_spin \fR=\fPint |
| Pretend to spend CPU time for given number of microseconds, sleeping the rest |
| 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. |
| Default: 1. |
| .TP |
| .BI rate \fR=\fPint |
| Cap bandwidth used by this job to this number of KiB/s. |
| .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. |
| .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. |
| .TP |
| .BI rate_iops_min \fR=\fPint |
| If this rate of I/O is not met, the job will exit. |
| .TP |
| .BI ratecycle \fR=\fPint |
| Average bandwidth for \fBrate\fR and \fBratemin\fR over this number of |
| milliseconds. Default: 1000ms. |
| .TP |
| .BI cpumask \fR=\fPint |
| Set CPU affinity for this job. \fIint\fR is a bitmask of allowed CPUs the job |
| may run on. See \fBsched_setaffinity\fR\|(2). |
| .TP |
| .BI cpus_allowed \fR=\fPstr |
| Same as \fBcpumask\fR, but allows a comma-delimited list of CPU numbers. |
| .TP |
| .BI startdelay \fR=\fPint |
| Delay start of job for the specified number of seconds. |
| .TP |
| .BI runtime \fR=\fPint |
| Terminate processing after the specified number of seconds. |
| .TP |
| .B time_based |
| If given, run for the specified \fBruntime\fR duration even if the files are |
| completely read or written. The same workload will be repeated as many times |
| as \fBruntime\fR allows. |
| .TP |
| .BI invalidate \fR=\fPbool |
| Invalidate buffer-cache for the file prior to starting I/O. Default: true. |
| .TP |
| .BI sync \fR=\fPbool |
| Use synchronous I/O for buffered writes. For the majority of I/O engines, |
| this means using O_SYNC. Default: false. |
| .TP |
| .BI iomem \fR=\fPstr "\fR,\fP mem" \fR=\fPstr |
| Allocation method for I/O unit buffer. Allowed values are: |
| .RS |
| .RS |
| .TP |
| .B malloc |
| Allocate memory with \fImalloc\fR\|(3). |
| .TP |
| .B shm |
| Use shared memory buffers allocated through \fIshmget\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 |
| is given after the option in the format `:\fIfile\fR'. |
| .TP |
| .B mmaphuge |
| Same as \fBmmap\fR, but use huge files as backing. |
| .RE |
| .P |
| The amount of memory allocated is the maximum allowed \fBblocksize\fR for the |
| job multiplied by \fBiodepth\fR. For \fBshmhuge\fR or \fBmmaphuge\fR to work, |
| the system must have free huge pages allocated. \fBmmaphuge\fR also needs to |
| have hugetlbfs mounted, and \fIfile\fR must point there. |
| .RE |
| .TP |
| .BI hugepage\-size \fR=\fPsiint |
| 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 |
| .B exitall |
| Terminate all jobs when one finishes. Default: wait for each job to finish. |
| .TP |
| .BI bwavgtime \fR=\fPint |
| Average bandwidth calculations over the given time in milliseconds. 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. |
| .TP |
| .BI unlink \fR=\fPbool |
| Unlink job files when done. Default: false. |
| .TP |
| .BI loops \fR=\fPint |
| Specifies the number of iterations (runs of the same workload) of this job. |
| Default: 1. |
| .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: |
| .RS |
| .RS |
| .TP |
| .B md5 crc16 crc32 crc64 crc7 sha256 sha512 |
| Store appropriate checksum in the header of each block. |
| .TP |
| .B meta |
| Write extra information about each I/O (timestamp, block number, etc.). The |
| block number is verified. |
| .TP |
| .B pattern |
| Fill I/O buffers with a specific pattern that is used to verify. The pattern is |
| specified by appending `:\fIint\fR' to the parameter. \fIint\fR cannot be larger |
| than 32-bits. |
| .TP |
| .B null |
| Pretend to verify. Used for testing internals. |
| .RE |
| .RE |
| .TP |
| .BI verify_sort \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 verify_offset \fR=\fPsiint |
| 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 |
| Write the verification header for this number of bytes, which should divide |
| \fBblocksize\fR. Default: \fBblocksize\fR. |
| .TP |
| .BI verify_fatal \fR=\fPbool |
| If true, exit the job on the first observed verification failure. Default: |
| false. |
| .TP |
| .B stonewall |
| Wait for preceeding jobs in the job file to exit before starting this one. |
| \fBstonewall\fR implies \fBnew_group\fR. |
| .TP |
| .B new_group |
| 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 numjobs \fR=\fPint |
| Number of clones (processes/threads performing the same workload) of this job. |
| Default: 1. |
| .TP |
| .B group_reporting |
| If set, display per-group reports instead of per-job when \fBnumjobs\fR is |
| specified. |
| .TP |
| .B thread |
| Use threads created with \fBpthread_create\fR\|(3) instead of processes created |
| with \fBfork\fR\|(2). |
| .TP |
| .BI zonesize \fR=\fPsiint |
| Divide file into zones of the specified size in bytes. See \fBzoneskip\fR. |
| .TP |
| .BI zoneskip \fR=\fPsiint |
| Skip the specified number of bytes when \fBzonesize\fR bytes of data have been |
| read. |
| .TP |
| .BI write_iolog \fR=\fPstr |
| Write the issued I/O patterns to the specified file. |
| .TP |
| .BI read_iolog \fR=\fPstr |
| 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. |
| .TP |
| .B write_lat_log |
| Same as \fBwrite_bw_log\fR, but writes I/O completion latencies. |
| .TP |
| .BI lockmem \fR=\fPsiint |
| Pin the specified amount of memory with \fBmlock\fR\|(2). Can be used to |
| simulate a smaller amount of memory. |
| .TP |
| .BI exec_prerun \fR=\fPstr |
| Before running the job, execute the specified command with \fBsystem\fR\|(3). |
| .TP |
| .BI exec_postrun \fR=\fPstr |
| Same as \fBexec_prerun\fR, but the command is executed after the job completes. |
| .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. |
| .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] |
| .RE |
| .P |
| The characters in the first set of brackets denote the current status of each |
| threads. The possible values are: |
| .P |
| .PD 0 |
| .RS |
| .TP |
| .B P |
| Setup but not started. |
| .TP |
| .B C |
| Thread created. |
| .TP |
| .B I |
| Initialized, waiting. |
| .TP |
| .B R |
| Running, doing sequential reads. |
| .TP |
| .B r |
| Running, doing random reads. |
| .TP |
| .B W |
| Running, doing sequential writes. |
| .TP |
| .B w |
| Running, doing random writes. |
| .TP |
| .B M |
| Running, doing mixed sequential reads/writes. |
| .TP |
| .B m |
| Running, doing mixed random reads/writes. |
| .TP |
| .B F |
| Running, currently waiting for \fBfsync\fR\|(2). |
| .TP |
| .B V |
| Running, verifying written data. |
| .TP |
| .B E |
| Exited, not reaped by main thread. |
| .TP |
| .B \- |
| Exited, thread reaped. |
| .RE |
| .PD |
| .P |
| The second set of brackets shows the estimated completion percentage of |
| the current group. The third set shows the read and write I/O rate, |
| respectively. Finally, the estimated run time of the job is displayed. |
| .P |
| When \fBfio\fR completes (or is interrupted by Ctrl-C), it will show data |
| for each thread, each group of threads, and each disk, in that order. |
| .P |
| Per-thread statistics first show the threads client number, group-id, and |
| error code. The remaining figures are as follows: |
| .RS |
| .TP |
| .B io |
| Number of megabytes of I/O performed. |
| .TP |
| .B bw |
| Average data rate (bandwidth). |
| .TP |
| .B runt |
| Threads run time. |
| .TP |
| .B slat |
| Submission latency minimum, maximum, average and standard deviation. This is |
| the time it took to submit the I/O. |
| .TP |
| .B clat |
| Completion latency minimum, maximum, average and standard deviation. This |
| is the time between submission and completion. |
| .TP |
| .B bw |
| Bandwidth minimum, maximum, percentage of aggregate bandwidth received, average |
| and standard deviation. |
| .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. |
| .TP |
| .B IO depths |
| Distribution of I/O depths. Each depth includes everything less than (or equal) |
| to it, but greater than the previous depth. |
| .TP |
| .B IO issued |
| Number of read/write requests issued, and number of short read/write requests. |
| .TP |
| .B IO latencies |
| Distribution of I/O completion latencies. The numbers follow the same pattern |
| as \fBIO depths\fR. |
| .RE |
| .P |
| The group statistics show: |
| .PD 0 |
| .RS |
| .TP |
| .B io |
| Number of megabytes I/O performed. |
| .TP |
| .B aggrb |
| Aggregate bandwidth of threads in the group. |
| .TP |
| .B minb |
| Minimum average bandwidth a thread saw. |
| .TP |
| .B maxb |
| Maximum average bandwidth a thread saw. |
| .TP |
| .B mint |
| Shortest runtime of threads in the group. |
| .TP |
| .B maxt |
| Longest runtime of threads in the group. |
| .RE |
| .PD |
| .P |
| Finally, disk statistics are printed with reads first: |
| .PD 0 |
| .RS |
| .TP |
| .B ios |
| Number of I/Os performed by all groups. |
| .TP |
| .B merge |
| Number of merges in the I/O scheduler. |
| .TP |
| .B ticks |
| Number of ticks we kept the disk busy. |
| .TP |
| .B io_queue |
| Total time spent in the disk queue. |
| .TP |
| .B util |
| Disk utilization. |
| .RE |
| .PD |
| .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. The fields are: |
| .P |
| .RS |
| .B jobname, groupid, error |
| .P |
| Read status: |
| .RS |
| .B KiB I/O, bandwidth \fR(KiB/s)\fP, runtime \fR(ms)\fP |
| .P |
| Submission latency: |
| .RS |
| .B min, max, mean, standard deviation |
| .RE |
| Completion latency: |
| .RS |
| .B min, max, mean, standard deviation |
| .RE |
| Bandwidth: |
| .RS |
| .B min, max, aggregate percentage of total, mean, standard deviation |
| .RE |
| .RE |
| .P |
| Write status: |
| .RS |
| .B KiB I/O, bandwidth \fR(KiB/s)\fP, runtime \fR(ms)\fP |
| .P |
| Submission latency: |
| .RS |
| .B min, max, mean, standard deviation |
| .RE |
| Completion latency: |
| .RS |
| .B min, max, mean, standard deviation |
| .RE |
| Bandwidth: |
| .RS |
| .B min, max, aggregate percentage of total, mean, standard deviation |
| .RE |
| .RE |
| .P |
| CPU usage: |
| .RS |
| .B user, system, context switches, major page faults, minor page faults |
| .RE |
| .P |
| IO depth distribution: |
| .RS |
| .B <=1, 2, 4, 8, 16, 32, >=64 |
| .RE |
| .P |
| IO latency distribution (ms): |
| .RS |
| .B <=2, 4, 10, 20, 50, 100, 250, 500, 750, 1000, >=2000 |
| .RE |
| .P |
| .B text description |
| .RE |
| .SH AUTHORS |
| .B fio |
| was written by Jens Axboe <jens.axboe@oracle.com>. |
| .br |
| 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>. |
| See \fBREADME\fR. |
| .SH "SEE ALSO" |
| For further documentation see \fBHOWTO\fR and \fBREADME\fR. |
| .br |
| Sample jobfiles are available in the \fBexamples\fR directory. |
| |