X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=181e94ca99a68c39c9f082916c89e0034fbfba62;hp=2a4f4d02398b434f43859e879c1e978fef9291be;hb=169c098dd3e2081679cf42978ea926e8dac62801;hpb=e0f01317e81e5de963734ba72996790b5adf732d diff --git a/HOWTO b/HOWTO index 2a4f4d02..181e94ca 100644 --- a/HOWTO +++ b/HOWTO @@ -297,7 +297,7 @@ irange Integer range with suffix. Allows value range to be given, such 1k:4k. If the option allows two sets of ranges, they can be specified with a ',' or '/' delimiter: 1k-4k/8k-32k. Also see int. -float_list A list of floating numbers, separated by a ':' character. +float_list A list of floating point numbers, separated by a ':' character. With the above in mind, here follows the complete list of fio job parameters. @@ -398,13 +398,15 @@ rw=str Type of io pattern. Accepted values are: read Sequential reads write Sequential writes + trim Sequential trims randwrite Random writes randread Random reads + randtrim Random trims rw,readwrite Sequential mixed reads and writes randrw Random mixed reads and writes - trimwrite Mixed trims and writes. Blocks will be - trimmed first, then written to. + trimwrite Sequential trim+write sequences + Fio defaults to read if the option is not specified. For the mixed io types, the default is to split them 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 @@ -443,7 +445,7 @@ kb_base=int The base unit for a kilobyte. The defacto base is 2^10, 1024. 1024 or 1000, with 1024 being the default. unified_rw_reporting=bool Fio normally reports statistics on a per - data direction basis, meaning that read, write, and trim are + data direction basis, meaning that reads, writes, and trims are accounted and reported separately. If this option is set, the fio will sum the results and report them as "mixed" instead. @@ -475,8 +477,17 @@ fadvise_hint=bool By default, fio will use fadvise() to advise the kernel on what IO patterns it is likely to issue. Sometimes you want to test specific IO patterns without telling the kernel about it, in which case you can disable this option. - If set, fio will use POSIX_FADV_SEQUENTIAL for sequential - IO and POSIX_FADV_RANDOM for random IO. + The following options are supported: + + sequential Use FADV_SEQUENTIAL + random Use FADV_RANDOM + 1 Backwards-compatible hint for basing + the hint on the fio workload. Will use + FADV_SEQUENTIAL for a sequential + workload, and FADV_RANDOM for a random + workload. + 0 Backwards-compatible setting for not + issing a fadvise hint. fadvise_stream=int Notify the kernel what write stream ID to place these writes under. Only supported on Linux. Note, this option @@ -699,7 +710,8 @@ ioengine=str Defines how the job issues io to the file. The following sync Basic read(2) or write(2) io. lseek(2) is used to position the io location. - psync Basic pread(2) or pwrite(2) io. + psync Basic pread(2) or pwrite(2) io. Default on all + supported operating systems except for Windows. vsync Basic readv(2) or writev(2) IO. @@ -717,6 +729,7 @@ ioengine=str Defines how the job issues io to the file. The following solarisaio Solaris native asynchronous io. windowsaio Windows native asynchronous io. + Default on Windows. mmap File is memory mapped and data copied to/from using memcpy(3). @@ -754,7 +767,8 @@ ioengine=str Defines how the job issues io to the file. The following 85% of the CPU. In case of SMP machines, use numjobs= to get desired CPU usage, as the cpuload only loads a single - CPU at the desired rate. + CPU at the desired rate. A job never finishes + unless there is at least one non-cpuio job. guasi The GUASI IO engine is the Generic Userspace Asyncronous Syscall Interface approach @@ -799,8 +813,8 @@ ioengine=str Defines how the job issues io to the file. The following cannot be modified. So random writes are not possible. To imitate this, libhdfs engine creates bunch of small files, and engine will - pick a file out of those files based on the - offset enerated by fio backend. Each jobs uses + pick a file out of those files based on the + offset generated by fio backend. Each jobs uses it's own connection to HDFS. mtd Read, write and erase an MTD character device @@ -815,6 +829,9 @@ ioengine=str Defines how the job issues io to the file. The following pmemblk Read and write through the NVML libpmemblk interface. + dev-dax Read and write through a DAX device exposed + from persistent memory. + external Prefix to specify loading an external IO engine object file. Append the engine filename, eg ioengine=external:/tmp/foo.o @@ -860,7 +877,7 @@ iodepth_batch_complete_max=int This defines maximum pieces of IO to iodepth_batch_complete_min=1 iodepth_batch_complete_max= - which means that we will retrieve at leat 1 IO and up to the + 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. @@ -982,7 +999,7 @@ random_distribution=str:float By default, fio will use a completely uniform random Uniform random distribution zipf Zipf distribution pareto Pareto distribution - gauss Normal (guassian) distribution + gauss Normal (gaussian) distribution zoned Zoned random distribution When using a zipf or pareto distribution, an input value @@ -1023,7 +1040,7 @@ percentage_random=int For a random workload, set how big a percentage should and random IO, at the given percentages. It is possible to set different values for reads, writes, and trim. To do so, simply use a comma separated list. See blocksize. - + norandommap Normally fio will cover every block of the file when doing random IO. If this option is given, fio will just get a new random offset without looking at past io history. This @@ -1062,9 +1079,14 @@ random_generator=str Fio supports the following engines for generating nice=int Run the job with the given nice value. See man nice(2). + On Windows, values less than -15 set the process class to "High"; + -1 through -15 set "Above Normal"; 1 through 15 "Below Normal"; + and above 15 "Idle" priority class. + prio=int Set the io priority value of this job. Linux limits us to a positive value between 0 and 7, with 0 being the highest. - See man ionice(1). + See man ionice(1). Refer to an appropriate manpage for + other operating systems since meaning of priority may differ. prioclass=int Set the io priority class. See man ionice(1). @@ -1170,13 +1192,13 @@ cpus_allowed_policy=str Set the policy of how fio distributes the CPUs one cpu per job. If not enough CPUs are given for the jobs listed, then fio will roundrobin the CPUs in the set. -numa_cpu_nodes=str Set this job running on spcified NUMA nodes' CPUs. The +numa_cpu_nodes=str Set this job running on specified NUMA nodes' CPUs. The arguments allow comma delimited list of cpu numbers, A-B ranges, or 'all'. Note, to enable numa options support, fio must be built on a system with libnuma-dev(el) installed. numa_mem_policy=str Set this job's memory policy and corresponding NUMA - nodes. Format of the argements: + nodes. Format of the arguments: [:] `mode' is one of the following memory policy: default, prefer, bind, interleave, local @@ -1209,6 +1231,48 @@ ramp_time=time If set, fio will run the specified workload for this amount thus it will increase the total runtime if a special timeout or runtime is specified. +steadystate=str:float +ss=str: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. Below is the + list of available steady state assessment criteria. 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. + 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). + iops_slope + Collect IOPS data and calculate the least + squares regression slope. Stop the job if the + slope falls below the specified limit. + bw Collect bandwidth data. Stop the job if all + individual bandwidth measurements are within + the specified limit of the mean bandwidth. + bw_slope + Collect bandwidth data and calculate the least + squares regression slope. Stop the job if the + slope falls below the specified limit. + +steadystate_duration=time +ss_dur=time 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. + +steadystate_ramp_time=time +ss_ramp=time 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. + invalidate=bool Invalidate the buffer/page cache parts for this file prior to starting io. Defaults to true. @@ -1220,6 +1284,7 @@ mem=str Fio can use various types of memory as the io unit buffer. The allowed values are: malloc Use memory from malloc(3) as the buffers. + Default memory type. shm Use shared memory as the buffers. Allocated through shmget(2). @@ -1256,7 +1321,7 @@ mem=str Fio can use various types of memory as the io unit buffer. location should point there. So if it's mounted in /huge, you would use mem=mmaphuge:/huge/somefile. -iomem_align=int This indiciates the memory alignment of the IO memory buffers. +iomem_align=int 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 iodepth the alignment of the following buffers are given by the bs used. In other words, if using a bs that is @@ -1289,7 +1354,7 @@ iopsavgtime=int Average the calculated IOPS over the given time. Value through 'write_iops_log', then the minimum of this option and 'log_avg_msec' will be used. Default: 500ms. -create_serialize=bool If true, serialize the file creating for the jobs. +create_serialize=bool If true, serialize the file creation for the jobs. This may be handy to avoid interleaving of data files, which may greatly depend on the filesystem used and even the number of processors in the system. @@ -1320,7 +1385,7 @@ pre_read=bool If this is given, files will be pre-read into memory before starting the given IO operation. This will also clear the 'invalidate' 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 + that are seek-able, since they allow you to read the same data multiple times. Thus it will not work on eg network or splice IO. @@ -1328,6 +1393,8 @@ unlink=bool Unlink the job files when done. Not the default, as repeated runs of that job would then waste time recreating the file set again and again. +unlink_each_loop=bool Unlink job files after each iteration or loop. + loops=int Run the specified number of iterations of this job. Used to repeat the same workload a given number of times. Defaults to 1. @@ -1360,7 +1427,7 @@ verify=str If writing to a file, fio can verify the file contents crc32c Use a crc32c sum of the data area and store it in the header of each block. - crc32c-intel Use hardware assisted crc32c calcuation + crc32c-intel Use hardware assisted crc32c calculation provided on SSE4.2 enabled processors. Falls back to regular software crc32c, if not supported by the system. @@ -1435,7 +1502,7 @@ verify_pattern=str If set, fio will fill the io buffers with this be a hex number that starts with either "0x" or "0X". Use with verify=str. Also, verify_pattern supports %o format, which means that for each block offset will be written and - then verifyied back, e.g.: + then verified back, e.g.: verify_pattern=%o @@ -1546,10 +1613,10 @@ read_iolog=str Open an iolog with the specified file name and replay the replay_no_stall=int When replaying I/O with read_iolog the default behavior is to attempt to respect the time stamps within the log and - replay them with the appropriate delay between IOPS. By + replay them with the appropriate delay between IOPS. By setting this variable fio will not respect the timestamps and attempt to replay them as fast as possible while still - respecting ordering. The result is the same I/O pattern to a + respecting ordering. The result is the same I/O pattern to a given device, but different timings. replay_redirect=str While replaying I/O patterns using read_iolog the @@ -1561,13 +1628,14 @@ replay_redirect=str While replaying I/O patterns using read_iolog the mapping. Replay_redirect causes all IOPS to be replayed onto the single specified device regardless of the device it was recorded from. i.e. replay_redirect=/dev/sdc would cause all - IO in the blktrace to be replayed onto /dev/sdc. This means - multiple devices will be replayed onto a single, if the trace - contains multiple devices. If you want multiple devices to be - replayed concurrently to multiple redirected devices you must - blkparse your trace into separate traces and replay them with - independent fio invocations. Unfortuantely this also breaks - the strict time ordering between multiple device accesses. + IO in the blktrace or iolog to be replayed onto /dev/sdc. + This means multiple devices will be replayed onto a single + device, if the trace contains multiple devices. If you want + multiple devices to be replayed concurrently to multiple + redirected devices you must blkparse your trace into separate + traces and replay them with independent fio invocations. + Unfortunately this also breaks the strict time ordering + between multiple device accesses. replay_align=int Force alignment of IO offsets and lengths in a trace to this power of 2 value. @@ -1600,10 +1668,18 @@ write_lat_log=str Same as write_bw_log, except that this option stores io The actual log names will be foo_slat.x.log, foo_clat.x.log, and foo_lat.x.log, where x is the index of the job (1..N, where N is the number of jobs). This helps fio_generate_plot - fine the logs automatically. If 'per_job_logs' is false, then + find the logs automatically. If 'per_job_logs' is false, then the filename will not include the job index. See 'Log File Formats'. +write_hist_log=str Same as write_lat_log, 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 per_job_logs is false, then the filename will not include the + job index. See 'Log File Formats'. + write_iops_log=str Same as write_bw_log, but writes IOPS. If no filename is given with this option, the default filename of "jobname_type.x.log" is used,where x is the index of the job @@ -1619,6 +1695,20 @@ log_avg_msec=int By default, fio will log an entry in the iops, latency, specified period of time, reducing the resolution of the log. See log_max_value as well. Defaults to 0, logging all entries. +log_hist_msec=int Same as log_avg_msec, but logs entries for completion + latency histograms. Computing latency percentiles from averages of + intervals using log_avg_msec 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 log_hist_coarseness as well. Defaults to 0, meaning histogram + logging is disabled. + +log_hist_coarseness=int Integer ranging from 0 to 6, defining the coarseness + of the resolution of the histogram logs enabled with log_hist_msec. For + each increment in coarseness, fio outputs half as many bins. Defaults to + 0, for which histogram logs contain 1216 latency bins. See + 'Log File Formats'. + log_max_value=bool If log_avg_msec 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 @@ -1651,6 +1741,10 @@ log_store_compressed=bool If set, fio will store the log files in a the --inflate-log command line parameter. The files will be stored with a .fz suffix. +log_unix_epoch=bool If set, fio will log Unix timestamps to the log + files produced by enabling write_type_log for each log type, instead + of the default zero-based timestamps. + block_error_percentiles=bool 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 @@ -1834,12 +1928,12 @@ that defines them is selected. [psyncv2] hipri Set RWF_HIPRI on IO, indicating to the kernel that it's of higher priority than normal. -[cpu] cpuload=int Attempt to use the specified percentage of CPU cycles. +[cpuio] cpuload=int Attempt to use the specified percentage of CPU cycles. -[cpu] cpuchunks=int Split the load into cycles of the given time. In +[cpuio] cpuchunks=int Split the load into cycles of the given time. In microseconds. -[cpu] exit_on_io_done=bool Detect when IO threads are done, then exit. +[cpuio] exit_on_io_done=bool Detect when IO threads are done, then exit. [netsplice] hostname=str [net] hostname=str The host name or IP address to use for TCP or UDP based IO. @@ -1885,7 +1979,7 @@ be the starting port number since fio will use a range of ports. connections rather than initiating an outgoing connection. The hostname must be omitted if this option is used. -[net] pingpong Normaly a network writer will just continue writing data, and +[net] pingpong Normally 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 payload to the reader, then wait for the reader to send the same payload back. This @@ -1906,22 +2000,22 @@ be the starting port number since fio will use a range of ports. [e4defrag] inplace=int Configure donor file blocks allocation strategy 0(default): Preallocate donor's file on init - 1 : allocate space immidietly inside defragment event, + 1 : allocate space immediately inside defragment event, and free right after event [rbd] clustername=str Specifies the name of the Ceph cluster. [rbd] rbdname=str Specifies the name of the RBD. -[rbd] pool=str Specifies the naem of the Ceph pool containing RBD. +[rbd] pool=str Specifies the name of the Ceph pool containing RBD. [rbd] clientname=str Specifies the username (without the 'client.' prefix) used to access the Ceph cluster. If the clustername is - specified, the clientmae shall be the full type.id + specified, the clientname shall be the full type.id string. If no type. prefix is given, fio will add 'client.' by default. [mtd] skip_bad=bool Skip operations against known bad blocks. [libhdfs] hdfsdirectory libhdfs will create chunk in this HDFS directory -[libhdfs] chunck_size the size of the chunck to use for each file. +[libhdfs] chunk_size the size of the chunk to use for each file. 6.0 Interpreting the output @@ -2314,10 +2408,9 @@ Data direction is one of the following: The offset is the offset, in bytes, from the start of the file, for that particular IO. The logging of the offset can be toggled with 'log_offset'. -If windowed logging is enabled though 'log_avg_msec', then fio doesn't log +If windowed logging is enabled through 'log_avg_msec', then fio doesn't log individual IOs. Instead of logs the average values over the specified period of time. Since 'data direction' and 'offset' are per-IO values, they aren't applicable if windowed logging is enabled. If windowed logging is enabled and 'log_max_value' is set, then fio logs maximum values in that window instead of averages. -