X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=a2503e9a6b73b093aee91c65ba2255f9cc690746;hp=804d93e4c578bfdb7d47058d177cce34420bb380;hb=5857e8e0f53e81bd7096209fe5cabf91ce74b853;hpb=3740cfc89440001e393dee1a6abae41ec89bec27 diff --git a/HOWTO b/HOWTO index 804d93e4..a2503e9a 100644 --- a/HOWTO +++ b/HOWTO @@ -100,6 +100,10 @@ Command line options Parse options only, don't start any I/O. +.. option:: --merge-blktrace-only + + Merge blktraces only, don't start any I/O. + .. option:: --output=filename Write output to file `filename`. @@ -194,7 +198,10 @@ Command line options Force a full status dump of cumulative (from job start) values at `time` intervals. This option does *not* provide per-period measurements. So values such as bandwidth are running averages. When the time unit is omitted, - `time` is interpreted in seconds. + `time` is interpreted in seconds. Note that using this option with + ``--output-format=json`` will yield output that technically isn't valid + json, since the output will be collated sets of valid json. It will need + to be split into valid sets of json after the run. .. option:: --section=name @@ -283,7 +290,8 @@ Command line options .. option:: --aux-path=path - Use this `path` for fio state generated files. + Use the directory specified by `path` for generated state files instead + of the current working directory. Any parameters following the options will be assumed to be job files, unless they match a job file parameter. Multiple job files can be listed and each job @@ -748,12 +756,15 @@ Target file/device assigned equally distributed to job clones created by :option:`numjobs` as long as they are using generated filenames. If specific `filename(s)` are set fio will use the first listed directory, and thereby matching the - `filename` semantic which generates a file each clone if not specified, but - let all clones use the same if set. + `filename` semantic (which generates a file for each clone if not + specified, but lets all clones use the same file if set). See the :option:`filename` option for information on how to escape "``:``" and "``\``" characters within the directory path itself. + Note: To control the directory fio will use for internal state files + use :option:`--aux-path`. + .. option:: filename=str Fio normally makes up a `filename` based on the job name, thread number, and @@ -948,18 +959,92 @@ Target file/device Unlink job files after each iteration or loop. Default: false. -.. option:: zonesize=int +.. option:: zonemode=str - Divide a file into zones of the specified size. See :option:`zoneskip`. + Accepted values are: + + **none** + The :option:`zonerange`, :option:`zonesize` and + :option:`zoneskip` parameters are ignored. + **strided** + I/O happens in a single zone until + :option:`zonesize` bytes have been transferred. + After that number of bytes has been + transferred processing of the next zone + starts. + **zbd** + Zoned block device mode. I/O happens + sequentially in each zone, even if random I/O + has been selected. Random I/O happens across + all zones instead of being restricted to a + single zone. The :option:`zoneskip` parameter + is ignored. :option:`zonerange` and + :option:`zonesize` must be identical. .. option:: zonerange=int - Give size of an I/O zone. See :option:`zoneskip`. + Size of a single zone. See also :option:`zonesize` and + :option:`zoneskip`. + +.. option:: zonesize=int + + For :option:`zonemode` =strided, this is the number of bytes to + transfer before skipping :option:`zoneskip` bytes. If this parameter + is smaller than :option:`zonerange` then only a fraction of each zone + with :option:`zonerange` bytes will be accessed. If this parameter is + larger than :option:`zonerange` then each zone will be accessed + multiple times before skipping to the next zone. + + For :option:`zonemode` =zbd, this is the size of a single zone. The + :option:`zonerange` parameter is ignored in this mode. .. option:: zoneskip=int - Skip the specified number of bytes when :option:`zonesize` data has been - read. The two zone options can be used to only do I/O on zones of a file. + For :option:`zonemode` =strided, the number of bytes to skip after + :option:`zonesize` bytes of data have been transferred. This parameter + must be zero for :option:`zonemode` =zbd. + +.. option:: read_beyond_wp=bool + + This parameter applies to :option:`zonemode` =zbd only. + + Zoned block devices are block devices that consist of multiple zones. + Each zone has a type, e.g. conventional or sequential. A conventional + zone can be written at any offset that is a multiple of the block + size. Sequential zones must be written sequentially. The position at + which a write must occur is called the write pointer. A zoned block + device can be either drive managed, host managed or host aware. For + host managed devices the host must ensure that writes happen + sequentially. Fio recognizes host managed devices and serializes + writes to sequential zones for these devices. + + If a read occurs in a sequential zone beyond the write pointer then + the zoned block device will complete the read without reading any data + from the storage medium. Since such reads lead to unrealistically high + bandwidth and IOPS numbers fio only reads beyond the write pointer if + explicitly told to do so. Default: false. + +.. option:: max_open_zones=int + + When running a random write test across an entire drive many more + zones will be open than in a typical application workload. Hence this + command line option that allows to limit the number of open zones. The + number of open zones is defined as the number of zones to which write + commands are issued. + +.. option:: zone_reset_threshold=float + + A number between zero and one that indicates the ratio of logical + blocks with data to the total number of logical blocks in the test + above which zones should be reset periodically. + +.. option:: zone_reset_frequency=float + + A number between zero and one that indicates how often a zone reset + should be issued if the zone reset threshold has been exceeded. A zone + reset is submitted after each (1 / zone_reset_frequency) write + requests. This and the previous parameter can be used to simulate + garbage collection activity. I/O type @@ -1825,6 +1910,15 @@ I/O engine (RBD) via librbd without the need to use the kernel rbd driver. This ioengine defines engine specific options. + **http** + I/O engine supporting GET/PUT requests over HTTP(S) with libcurl to + a WebDAV or S3 endpoint. This ioengine defines engine specific options. + + This engine only supports direct IO of iodepth=1; you need to scale this + via numjobs. blocksize defines the size of the objects to be created. + + TRIM is translated to object deletion. + **gfapi** Using GlusterFS libgfapi sync interface to direct access to GlusterFS volumes without having to go through FUSE. This ioengine @@ -1882,6 +1976,22 @@ I/O engine mounted with DAX on a persistent memory device through the PMDK libpmem library. + **ime_psync** + Synchronous read and write using DDN's Infinite Memory Engine (IME). + This engine is very basic and issues calls to IME whenever an IO is + queued. + + **ime_psyncv** + Synchronous read and write using DDN's Infinite Memory Engine (IME). + This engine uses iovecs and will try to stack as much IOs as possible + (if the IOs are "contiguous" and the IO depth is not exceeded) + before issuing a call to IME. + + **ime_aio** + 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. + I/O engine specific parameters ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -2105,6 +2215,54 @@ with the caveat that when used on the command line, they must come after the transferred to the device. The writefua option is ignored with this selection. +.. option:: http_host=str : [http] + + Hostname to connect to. For S3, this could be the bucket hostname. + Default is **localhost** + +.. option:: http_user=str : [http] + + Username for HTTP authentication. + +.. option:: http_pass=str : [http] + + Password for HTTP authentication. + +.. option:: https=str : [http] + + Enable HTTPS instead of http. *on* enables HTTPS; *insecure* + will enable HTTPS, but disable SSL peer verification (use with + caution!). Default is **off** + +.. option:: http_mode=str : [http] + + Which HTTP access mode to use: *webdav*, *swift*, or *s3*. + Default is **webdav** + +.. option:: http_s3_region=str : [http] + + The S3 region/zone string. + Default is **us-east-1** + +.. option:: http_s3_key=str : [http] + + The S3 secret key. + +.. option:: http_s3_keyid=str : [http] + + The S3 key/access id. + +.. option:: http_swift_auth_token=str : [http] + + The Swift auth token. See the example configuration file on how + to retrieve this. + +.. option:: http_verbose=int : [http] + + Enable verbose requests from libcurl. Useful for debugging. 1 + turns on verbose logging from libcurl, 2 additionally enables + HTTP IO tracing. Default is **0** + I/O depth ~~~~~~~~~ @@ -2326,6 +2484,43 @@ I/O replay :manpage:`blktrace(8)` for how to capture such logging data. For blktrace replay, the file needs to be turned into a blkparse binary data file first (``blkparse -o /dev/null -d file_for_fio.bin``). + You can specify a number of files by separating the names with a ':' + character. See the :option:`filename` option for information on how to + escape ':' and '\' characters within the file names. These files will + be sequentially assigned to job clones created by :option:`numjobs`. + +.. option:: read_iolog_chunked=bool + + Determines how iolog is read. If false(default) entire :option:`read_iolog` + will be read at once. If selected true, input from iolog will be read + gradually. Useful when iolog is very large, or it is generated. + +.. option:: merge_blktrace_file=str + + When specified, rather than replaying the logs passed to :option:`read_iolog`, + the logs go through a merge phase which aggregates them into a single + blktrace. The resulting file is then passed on as the :option:`read_iolog` + parameter. The intention here is to make the order of events consistent. + This limits the influence of the scheduler compared to replaying multiple + blktraces via concurrent jobs. + +.. option:: merge_blktrace_scalars=float_list + + This is a percentage based option that is index paired with the list of + files passed to :option:`read_iolog`. When merging is performed, scale + the time of each event by the corresponding amount. For example, + ``--merge_blktrace_scalars="50:100"`` runs the first trace in halftime + and the second trace in realtime. This knob is separately tunable from + :option:`replay_time_scale` which scales the trace during runtime and + does not change the output of the merge unlike this option. + +.. option:: merge_blktrace_iters=float_list + + This is a whole number option that is index paired with the list of files + passed to :option:`read_iolog`. When merging is performed, run each trace + for the specified number of iterations. For example, + ``--merge_blktrace_iters="2:1"`` runs the first trace for two iterations + and the second trace for one iteration. .. option:: replay_no_stall=bool @@ -2364,12 +2559,13 @@ 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 @@ -2805,6 +3001,10 @@ Steady state 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. + When using this feature, most jobs should include the :option:`time_based` + and :option:`runtime` options or the :option:`loops` option so that fio does not + stop running after it has covered the full size of the specified file(s) or device(s). + **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`` @@ -2909,9 +3109,11 @@ Measurements and reporting .. option:: write_iops_log=str Same as :option:`write_bw_log`, but writes an IOPS file (e.g. - :file:`name_iops.x.log`) instead. See :option:`write_bw_log` for - details about the filename format and `Log File Formats`_ for how data - is structured within the file. + :file:`name_iops.x.log`) instead. Because fio defaults to individual + I/O logging, the value entry in the IOPS log will be 1 unless windowed + logging (see :option:`log_avg_msec`) has been enabled. See + :option:`write_bw_log` for details about the filename format and `Log + File Formats`_ for how data is structured within the file. .. option:: log_avg_msec=int @@ -3673,6 +3875,46 @@ given in bytes. The `action` can be one of these: **trim** Trim the given file from the given `offset` for `length` bytes. + +I/O Replay - Merging Traces +--------------------------- + +Colocation is a common practice used to get the most out of a machine. +Knowing which workloads play nicely with each other and which ones don't is +a much harder task. While fio can replay workloads concurrently via multiple +jobs, it leaves some variability up to the scheduler making results harder to +reproduce. Merging is a way to make the order of events consistent. + +Merging is integrated into I/O replay and done when a +:option:`merge_blktrace_file` is specified. The list of files passed to +:option:`read_iolog` go through the merge process and output a single file +stored to the specified file. The output file is passed on as if it were the +only file passed to :option:`read_iolog`. An example would look like:: + + $ fio --read_iolog=":" --merge_blktrace_file="" + +Creating only the merged file can be done by passing the command line argument +:option:`merge-blktrace-only`. + +Scaling traces can be done to see the relative impact of any particular trace +being slowed down or sped up. :option:`merge_blktrace_scalars` takes in a colon +separated list of percentage scalars. It is index paired with the files passed +to :option:`read_iolog`. + +With scaling, it may be desirable to match the running time of all traces. +This can be done with :option:`merge_blktrace_iters`. It is index paired with +:option:`read_iolog` just like :option:`merge_blktrace_scalars`. + +In an example, given two traces, A and B, each 60s long. If we want to see +the impact of trace A issuing IOs twice as fast and repeat trace A over the +runtime of trace B, the following can be done:: + + $ fio --read_iolog=":"" --merge_blktrace_file"" --merge_blktrace_scalars="50:100" --merge_blktrace_iters="2:1" + +This runs trace A at 2x the speed twice for approximately the same runtime as +a single run of trace B. + + CPU idleness profiling ---------------------- @@ -3796,17 +4038,16 @@ on the type of log, it will be one of the following: **2** I/O is a TRIM -The entry's *block size* is always in bytes. The *offset* is the offset, in bytes, -from the start of the file, for that particular I/O. The logging of the offset can be +The entry's *block size* is always in bytes. The *offset* is the position in bytes +from the start of the file for that particular I/O. The logging of the offset can be toggled with :option:`log_offset`. -Fio defaults to logging every individual I/O. When IOPS are logged for individual -I/Os the *value* entry will always be 1. If windowed logging is enabled through -:option:`log_avg_msec`, fio logs the average values over the specified period of time. -If windowed logging is enabled and :option:`log_max_value` is set, then fio logs -maximum values in that window instead of averages. Since *data direction*, *block -size* and *offset* are per-I/O values, if windowed logging is enabled they -aren't applicable and will be 0. +Fio defaults to logging every individual I/O but when windowed logging is set +through :option:`log_avg_msec`, either the average (by default) or the maximum +(:option:`log_max_value` is set) *value* seen over the specified period of time +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 -------------