X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=6b449e97029b674525983ac158e5b40881f1b733;hp=95289040dd3fd58a0bb70dfb0a94fadf1475e175;hb=f6abd73197dd534a4944eabfdd11f5104fcf9409;hpb=843c6b5e081900394da002b45253e541b794ac54 diff --git a/HOWTO b/HOWTO index 95289040..6b449e97 100644 --- a/HOWTO +++ b/HOWTO @@ -93,6 +93,12 @@ Command line options Dump info related to I/O rate switching. *compress* Dump info related to log compress/decompress. + *steadystate* + Dump info related to steadystate detection. + *helperthread* + Dump info related to the helper thread. + *zbd* + Dump info related to support for zoned block devices. *?* or *help* Show available debug options. @@ -1246,7 +1252,9 @@ I/O type is incremented for each sub-job (i.e. when :option:`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. + spacing between the starting points. Percentages can be used for this option. + If a percentage is given, the generated offset will be aligned to the minimum + ``blocksize`` or to the value of ``offset_align`` if provided. .. option:: number_ios=int @@ -1805,6 +1813,11 @@ I/O engine **pvsync2** Basic :manpage:`preadv2(2)` or :manpage:`pwritev2(2)` I/O. + **io_uring** + Fast Linux native asynchronous I/O. Supports async IO + for both direct and buffered IO. + This engine defines engine specific options. + **libaio** Linux native asynchronous I/O. Note that Linux may only support queued behavior with non-buffered I/O (set ``direct=1`` or @@ -1991,6 +2004,10 @@ I/O engine Asynchronous read and write using DDN's Infinite Memory Engine (IME). This engine will try to stack as much IOs as possible by creating requests for IME. FIO will then decide when to commit these requests. + **libiscsi** + Read and write iscsi lun with libiscsi. + **nbd** + Read and write a Network Block Device (NBD). I/O engine specific parameters ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -2000,6 +2017,41 @@ In addition, there are some parameters which are only valid when a specific with the caveat that when used on the command line, they must come after the :option:`ioengine` that defines them is selected. +.. option:: hipri : [io_uring] + + If this option is set, fio will attempt to use polled IO completions. + Normal IO completions generate interrupts to signal the completion of + IO, polled completions do not. Hence they are require active reaping + by the application. The benefits are more efficient IO for high IOPS + scenarios, and lower latencies for low queue depth IO. + +.. option:: fixedbufs : [io_uring] + + If fio is asked to do direct IO, then Linux will map pages for each + IO call, and release them when IO is done. If this option is set, the + pages are pre-mapped before IO is started. This eliminates the need to + map and release for each IO. This is more efficient, and reduces the + IO latency as well. + +.. option:: registerfiles : [io_uring] + With this option, fio registers the set of files being used with the + kernel. This avoids the overhead of managing file counts in the kernel, + making the submission and completion part more lightweight. Required + for the below :option:`sqthread_poll` option. + +.. option:: sqthread_poll : [io_uring] + + Normally fio will submit IO by issuing a system call to notify the + kernel of available items in the SQ ring. If this option is set, the + act of submitting IO will be done by a polling thread in the kernel. + This frees up cycles for fio, at the cost of using more CPU in the + system. + +.. option:: sqthread_poll_cpu : [io_uring] + + When :option:`sqthread_poll` is set, this option provides a way to + define which CPU should be used for the polling thread. + .. option:: userspace_reap : [libaio] Normally, with the libaio engine in use, fio will use the @@ -2263,6 +2315,15 @@ with the caveat that when used on the command line, they must come after the turns on verbose logging from libcurl, 2 additionally enables HTTP IO tracing. Default is **0** +.. option:: uri=str : [nbd] + + Specify the NBD URI of the server to test. The string + is a standard NBD URI + (see https://github.com/NetworkBlockDevice/nbd/tree/master/doc). + Example URIs: nbd://localhost:10809 + nbd+unix:///?socket=/tmp/socket + nbds://tlshost/exportname + I/O depth ~~~~~~~~~ @@ -2339,8 +2400,13 @@ I/O depth ``serialize_overlap`` tells fio to avoid provoking this behavior by explicitly serializing in-flight I/Os that have a non-zero overlap. Note that setting this option can reduce both performance and the :option:`iodepth` achieved. - Additionally this option does not work when :option:`io_submit_mode` is set to - offload. Default: false. + + This option only applies to I/Os issued for a single job except when it is + enabled along with :option:`io_submit_mode`\=offload. In offload mode, fio + will check for overlap among all I/Os submitted by offload jobs with :option:`serialize_overlap` + enabled. + + Default: false. .. option:: io_submit_mode=str @@ -2559,12 +2625,13 @@ I/O replay .. option:: replay_align=int - Force alignment of I/O offsets and lengths in a trace to this power of 2 - value. + Force alignment of the byte offsets in a trace to this value. The value + must be a power of 2. .. option:: replay_scale=int - Scale sector offsets down by this factor when replaying traces. + Scale byte offsets down by this factor when replaying traces. Should most + likely use :option:`replay_align` as well. .. option:: replay_skip=str @@ -3685,7 +3752,8 @@ is one long line of values, such as:: 2;card0;0;0;7139336;121836;60004;1;10109;27.932460;116.933948;220;126861;3495.446807;1085.368601;226;126864;3523.635629;1089.012448;24063;99944;50.275485%;59818.274627;5540.657370;7155060;122104;60004;1;8338;29.086342;117.839068;388;128077;5032.488518;1234.785715;391;128085;5061.839412;1236.909129;23436;100928;50.287926%;59964.832030;5644.844189;14.595833%;19.394167%;123706;0;7313;0.1%;0.1%;0.1%;0.1%;0.1%;0.1%;100.0%;0.00%;0.00%;0.00%;0.00%;0.00%;0.00%;0.01%;0.02%;0.05%;0.16%;6.04%;40.40%;52.68%;0.64%;0.01%;0.00%;0.01%;0.00%;0.00%;0.00%;0.00%;0.00% A description of this job goes here. -The job description (if provided) follows on a second line. +The job description (if provided) follows on a second line for terse v2. +It appears on the same line for other terse versions. To enable terse output, use the :option:`--minimal` or :option:`--output-format`\=terse command line options. The @@ -3770,6 +3838,11 @@ minimal output v3, separated by semicolons:: 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_min;read_clat_max;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_min;write_clat_max;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;cpu_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 +In client/server mode terse output differs from what appears when jobs are run +locally. Disk utilization data is omitted from the standard terse output and +for v3 and later appears on its own separate line at the end of each terse +reporting cycle. + JSON output ------------ @@ -4048,6 +4121,7 @@ is recorded. Each *data direction* seen within the window period will aggregate its values in a separate row. Further, when using windowed logging the *block size* and *offset* entries will always contain 0. + Client/Server ------------- @@ -4135,3 +4209,6 @@ containing two hostnames ``h1`` and ``h2`` with IP addresses 192.168.10.120 and /mnt/nfs/fio/192.168.10.120.fileio.tmp /mnt/nfs/fio/192.168.10.121.fileio.tmp + +Terse output in client/server mode will differ slightly from what is produced +when fio is run in stand-alone mode. See the terse output section for details.