X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=HOWTO;h=fe5c3cb193e9172275e0df47730158309fd33e5b;hp=92c3b7371219bfc2bccbf46836d5c9d41232eae1;hb=dad0ea54b595ad656aca4087014afb438c7d44f0;hpb=586631b8caf1bfba2e23ecd0703dbc3fa9b16bc0 diff --git a/HOWTO b/HOWTO index 92c3b737..fe5c3cb1 100644 --- a/HOWTO +++ b/HOWTO @@ -54,56 +54,66 @@ Command line options .. option:: --debug=type - Enable verbose tracing of various fio actions. May be ``all`` for all types - or individual types separated by a comma (e.g. ``--debug=file,mem`` will - enable file and memory debugging). Currently, additional logging is - available for: + Enable verbose tracing of various fio actions. May be ``all`` for all types + or individual types separated by a comma (e.g. ``--debug=file,mem`` will + enable file and memory debugging). Currently, additional logging is + available for: - *process* + *process* Dump info related to processes. - *file* + *file* Dump info related to file actions. - *io* + *io* Dump info related to I/O queuing. - *mem* + *mem* Dump info related to memory allocations. - *blktrace* + *blktrace* Dump info related to blktrace setup. - *verify* + *verify* Dump info related to I/O verification. - *all* + *all* Enable all debug options. - *random* + *random* Dump info related to random offset generation. - *parse* + *parse* Dump info related to option matching and parsing. - *diskutil* + *diskutil* Dump info related to disk utilization updates. - *job:x* + *job:x* Dump info only related to job number x. - *mutex* + *mutex* Dump info only related to mutex up/down ops. - *profile* + *profile* Dump info related to profile extensions. - *time* + *time* Dump info related to internal time keeping. - *net* + *net* Dump info related to networking connections. - *rate* + *rate* Dump info related to I/O rate switching. - *compress* + *compress* Dump info related to log compress/decompress. - *?* or *help* + *?* or *help* Show available debug options. .. option:: --parse-only - Parse options only, don\'t start any I/O. + Parse options only, don't start any I/O. .. option:: --output=filename Write output to file `filename`. +.. option:: --output-format=type + + Set the reporting format to `normal`, `terse`, `json`, or `json+`. Multiple + formats can be selected, separated by a comma. `terse` is a CSV based + format. `json+` is like `json`, except it adds a full dump of the latency + buckets. + +.. option:: --runtime + Limit run time to runtime seconds. + .. option:: --bandwidth-log Generate aggregate bandwidth logs. @@ -114,16 +124,9 @@ Command line options .. option:: --append-terse - Print statistics in selected mode AND terse, semicolon-delimited format. - **deprecated**, use :option:`--output-format` instead to select multiple - formats. - -.. option:: --output-format=type - - Set the reporting format to `normal`, `terse`, `json`, or `json+`. Multiple - formats can be selected, separated by a comma. `terse` is a CSV based - format. `json+` is like `json`, except it adds a full dump of the latency - buckets. + Print statistics in selected mode AND terse, semicolon-delimited format. + **Deprecated**, use :option:`--output-format` instead to select multiple + formats. .. option:: --terse-version=type @@ -131,7 +134,7 @@ Command line options .. option:: --version - Print version info and exit. + Print version information and exit. .. option:: --help @@ -143,9 +146,9 @@ Command line options .. option:: --crctest=[test] - Test the speed of the built-in checksumming functions. If no argument is - given all of them are tested. Alternatively, a comma separated list can be passed, in - which case the given ones are tested. + Test the speed of the built-in checksumming functions. If no argument is + given, all of them are tested. Alternatively, a comma separated list can + be passed, in which case the given ones are tested. .. option:: --cmdhelp=command @@ -153,27 +156,27 @@ Command line options .. option:: --enghelp=[ioengine[,command]] - List all commands defined by :option:`ioengine`, or print help for `command` - defined by :option:`ioengine`. If no :option:`ioengine` is given, list all - available ioengines. + List all commands defined by :option:`ioengine`, or print help for `command` + defined by :option:`ioengine`. If no :option:`ioengine` is given, list all + available ioengines. .. option:: --showcmd=jobfile - Turn a job file into command line options. + Convert `jobfile` to a set of command-line options. .. option:: --readonly - Turn on safety read-only checks, preventing writes. The ``--readonly`` - option is an extra safety guard to prevent users from accidentally starting - a write workload when that is not desired. Fio will only write if - `rw=write/randwrite/rw/randrw` is given. This extra safety net can be used - as an extra precaution as ``--readonly`` will also enable a write check in - the I/O engine core to prevent writes due to unknown user space bug(s). + Turn on safety read-only checks, preventing writes. The ``--readonly`` + option is an extra safety guard to prevent users from accidentally starting + a write workload when that is not desired. Fio will only write if + `rw=write/randwrite/rw/randrw` is given. This extra safety net can be used + as an extra precaution as ``--readonly`` will also enable a write check in + the I/O engine core to prevent writes due to unknown user space bug(s). .. option:: --eta=when - When real-time ETA estimate should be printed. May be `always`, `never` or - `auto`. + Specifies when real-time ETA estimate should be printed. `when` may be + `always`, `never` or `auto`. .. option:: --eta-newline=time @@ -187,48 +190,48 @@ Command line options .. option:: --section=name - Only run specified section in job file. Multiple sections can be specified. - The ``--section`` option allows one to combine related jobs into one file. - E.g. one job file could define light, moderate, and heavy sections. Tell - fio to run only the "heavy" section by giving ``--section=heavy`` - command line option. One can also specify the "write" operations in one - section and "verify" operation in another section. The ``--section`` option - only applies to job sections. The reserved *global* section is always - parsed and used. + Only run specified section `name` in job file. Multiple sections can be specified. + The ``--section`` option allows one to combine related jobs into one file. + E.g. one job file could define light, moderate, and heavy sections. Tell + fio to run only the "heavy" section by giving ``--section=heavy`` + command line option. One can also specify the "write" operations in one + section and "verify" operation in another section. The ``--section`` option + only applies to job sections. The reserved *global* section is always + parsed and used. .. option:: --alloc-size=kb - Set the internal smalloc pool to this size in KiB. The - ``--alloc-size`` switch allows one to use a larger pool size for smalloc. - If running large jobs with randommap enabled, fio can run out of memory. - Smalloc is an internal allocator for shared structures from a fixed size - memory pool and can grow to 16 pools. The pool size defaults to 16MiB. + Set the internal smalloc pool size to `kb` in KiB. The + ``--alloc-size`` switch allows one to use a larger pool size for smalloc. + If running large jobs with randommap enabled, fio can run out of memory. + Smalloc is an internal allocator for shared structures from a fixed size + memory pool and can grow to 16 pools. The pool size defaults to 16MiB. - NOTE: While running :file:`.fio_smalloc.*` backing store files are visible - in :file:`/tmp`. + NOTE: While running :file:`.fio_smalloc.*` backing store files are visible + in :file:`/tmp`. .. option:: --warnings-fatal - All fio parser warnings are fatal, causing fio to exit with an - error. + All fio parser warnings are fatal, causing fio to exit with an + error. .. option:: --max-jobs=nr - Maximum number of threads/processes to support. + Set the maximum number of threads/processes to support. .. option:: --server=args - Start a backend server, with `args` specifying what to listen to. - See `Client/Server`_ section. + Start a backend server, with `args` specifying what to listen to. + See `Client/Server`_ section. .. option:: --daemonize=pidfile - Background a fio server, writing the pid to the given `pidfile` file. + Background a fio server, writing the pid to the given `pidfile` file. .. option:: --client=hostname - Instead of running the jobs locally, send and run them on the given host or - set of hosts. See `Client/Server`_ section. + Instead of running the jobs locally, send and run them on the given host or + set of hosts. See `Client/Server`_ section. .. option:: --remote-config=file @@ -236,7 +239,7 @@ Command line options .. option:: --idle-prof=option - Report CPU idleness. *option* is one of the following: + Report CPU idleness. `option` is one of the following: **calibrate** Run unit work calibration only and exit. @@ -445,7 +448,7 @@ automatically substituted with the current system values when the job is run. Simple math is also supported on these keywords, so you can perform actions like:: - size=8*$mb_memory + size=8*$mb_memory and get that properly expanded to 8 times the size of memory in the machine. @@ -474,7 +477,7 @@ Parameter types ~~~~~~~~~~~~~~~ **str** - String. This is a sequence of alpha characters. + String: A sequence of alphanumeric characters. **time** Integer with possible time suffix. Without a unit value is interpreted as @@ -488,7 +491,7 @@ Parameter types Integer. A whole number value, which may contain an integer prefix and an integer suffix: - [*integer prefix*] **number** [*integer suffix*] + [*integer prefix*] **number** [*integer suffix*] The optional *integer prefix* specifies the number's base. The default is decimal. *0x* specifies hexadecimal. @@ -521,7 +524,7 @@ Parameter types compatibility with old scripts. For example, 4k means 4096. For quantities of data, an optional unit of 'B' may be included - (e.g., 'kB' is the same as 'k'). + (e.g., 'kB' is the same as 'k'). The *integer suffix* is not case sensitive (e.g., m/mi mean mebi/mega, not milli). 'b' and 'B' both mean byte, not bit. @@ -1012,8 +1015,8 @@ I/O type ``sequential`` is only useful for random I/O, where fio would normally generate a new random offset for every I/O. If you append e.g. 8 to randread, - you would get a new random offset for every 8 I/O's. The result would be a - seek for only every 8 I/O's, instead of for every I/O. Use ``rw=randread:8`` + you would get a new random offset for every 8 I/Os. The result would be a + seek for only every 8 I/Os, instead of for every I/O. Use ``rw=randread:8`` to specify that. As sequential I/O is already sequential, setting ``sequential`` for that would not result in any differences. ``identical`` behaves in a similar fashion, except it sends the same offset 8 number of @@ -1090,11 +1093,29 @@ I/O type **random** Advise using **FADV_RANDOM**. -.. option:: fadvise_stream=int +.. option:: write_hint=str + + Use :manpage:`fcntl(2)` to advise the kernel what life time to expect + from a write. Only supported on Linux, as of version 4.13. Accepted + values are: + + **none** + No particular life time associated with this file. + + **short** + Data written to this file has a short life time. + + **medium** + Data written to this file has a medium life time. + + **long** + Data written to this file has a long life time. + + **extreme** + Data written to this file has a very long life time. - Use :manpage:`posix_fadvise(2)` to advise the kernel what stream ID the - writes issued belong to. Only supported on Linux. Note, this option may - change going forward. + The values are all relative to each other, and no absolute meaning + should be associated with them. .. option:: offset=int @@ -1234,7 +1255,7 @@ I/O type * 60% of accesses should be to the first 10% * 30% of accesses should be to the next 20% - * 8% of accesses should be to to the next 30% + * 8% of accesses should be to the next 30% * 2% of accesses should be to the next 40% we can define that through zoning of the random accesses. For the above @@ -1868,13 +1889,13 @@ caveat that when used on the command line, they must come after the hostname if the job is a TCP listener or UDP reader. For unix sockets, the normal filename option should be used and the port is invalid. -.. option:: listen : [net] +.. option:: listen : [netsplice] [net] For TCP network connections, tell fio to listen for incoming connections rather than initiating an outgoing connection. The :option:`hostname` must be omitted if this option is used. -.. option:: pingpong : [net] +.. option:: pingpong : [netsplice] [net] 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 @@ -1886,11 +1907,11 @@ caveat that when used on the command line, they must come after the ``pingpong=1`` should only be set for a single reader when multiple readers are listening to the same address. -.. option:: window_size : [net] +.. option:: window_size : [netsplice] [net] Set the desired socket buffer size for the connection. -.. option:: mss : [net] +.. option:: mss : [netsplice] [net] Set the TCP maximum segment size (TCP_MAXSEG). @@ -2740,7 +2761,8 @@ Measurements and reporting .. option:: log_offset=int If this is set, the iolog options will include the byte offset for the I/O - entry as well as the other data values. + entry as well as the other data values. Defaults to 0 meaning that + offsets are not present in logs. Also see `Log File Formats`_. .. option:: log_compression=int @@ -3221,7 +3243,7 @@ numbers denote: **ios** Number of I/Os performed by all groups. **merge** - Number of merges I/O the I/O scheduler. + Number of merges performed by the I/O scheduler. **ticks** Number of ticks we kept the disk busy. **in_queue** @@ -3257,7 +3279,7 @@ changed for some reason, this number will be incremented by 1 to signify that change. Split up, the format is as follows (comments in brackets denote when a -field was introduced or whether its specific to some terse version): +field was introduced or whether it's specific to some terse version): :: @@ -3510,9 +3532,10 @@ Log File Formats Fio supports a variety of log file formats, for logging latencies, bandwidth, and IOPS. The logs share a common format, which looks like this: - *time* (`msec`), *value*, *data direction*, *offset* + *time* (`msec`), *value*, *data direction*, *block size* (`bytes`), + *offset* (`bytes`) -Time for the log entry is always in milliseconds. The *value* logged depends +*Time* for the log entry is always in milliseconds. The *value* logged depends on the type of log, it will be one of the following: **Latency log** @@ -3531,18 +3554,19 @@ on the type of log, it will be one of the following: **2** I/O is a TRIM -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 toggled with -:option:`log_offset`. +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 +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 +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' and -'offset' are per-I/O values, they aren't applicable if windowed logging is enabled. +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. -Client/server +Client/Server ------------- Normally fio is invoked as a stand-alone application on the machine where the