.. option:: runtime=time
- Tell fio to terminate processing after the specified period of time. It
- can be quite hard to determine for how long a specified job will run, so
- this parameter is handy to cap the total runtime to a given time. When
- the unit is omitted, the value is interpreted in seconds.
+ Limit runtime. The test will run until it completes the configured I/O
+ workload or until it has run for this specified amount of time, whichever
+ occurs first. It can be quite hard to determine for how long a specified
+ job will run, so this parameter is handy to cap the total runtime to a
+ given time. When the unit is omitted, the value is interpreted in
+ seconds.
.. option:: time_based
.. option:: randrepeat=bool
- Seed the random number generator used for random I/O patterns in a
- predictable way so the pattern is repeatable across runs. Default: true.
+ Seed all random number generators in a predictable way so the pattern
+ is repeatable across runs. Default: true.
.. option:: allrandrepeat=bool
- Seed all random number generators in a predictable way so results are
- repeatable across runs. Default: false.
+ Alias for :option:`randrepeat`. Default: true.
.. option:: randseed=int
**random**
Advise using **FADV_RANDOM**.
+ **noreuse**
+ Advise using **FADV_NOREUSE**. This may be a no-op on older Linux
+ kernels. Since Linux 6.3, it provides a hint to the LRU algorithm.
+ See the :manpage:`posix_fadvise(2)` man page.
+
.. option:: write_hint=str
Use :manpage:`fcntl(2)` to advise the kernel what life time to expect
performance. The default is to enable it only if
:option:`libblkio_wait_mode=eventfd <libblkio_wait_mode>`.
+.. option:: no_completion_thread : [windowsaio]
+
+ Avoid using a separate thread for completion polling.
+
I/O depth
~~~~~~~~~
fio will ignore the thinktime and continue doing IO at the specified
rate, instead of entering a catch-up mode after thinktime is done.
+.. option:: rate_cycle=int
+
+ Average bandwidth for :option:`rate` and :option:`rate_min` over this number
+ of milliseconds. Defaults to 1000.
+
I/O latency
~~~~~~~~~~~
microseconds. Comma-separated values may be specified for reads, writes,
and trims as described in :option:`blocksize`.
-.. option:: rate_cycle=int
-
- Average bandwidth for :option:`rate` and :option:`rate_min` over this number
- of milliseconds. Defaults to 1000.
-
I/O replay
~~~~~~~~~~
verification pass, according to the settings in the job file used. Default
false.
+.. option:: experimental_verify=bool
+
+ Enable experimental verification. Standard verify records I/O metadata
+ for later use during the verification phase. Experimental verify
+ instead resets the file after the write phase and then replays I/Os for
+ the verification phase.
+
.. option:: trim_percentage=int
Number of verify blocks to discard/trim.
Trim this number of I/O blocks.
-.. option:: experimental_verify=bool
-
- Enable experimental verification. Standard verify records I/O metadata
- for later use during the verification phase. Experimental verify
- instead resets the file after the write phase and then replays I/Os for
- the verification phase.
-
Steady state
~~~~~~~~~~~~
.. option:: 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. When the unit is omitted, the
- value is interpreted in seconds.
+ A rolling window of this duration will be used to judge whether steady
+ state has been reached. Data will be collected every
+ :option:`ss_interval`. The default is 0 which disables steady state
+ detection. When the unit is omitted, the value is interpreted in
+ seconds.
.. option:: steadystate_ramp_time=time, ss_ramp=time
collection for checking the steady state job termination criterion. The
default is 0. When the unit is omitted, the value is interpreted in seconds.
+.. option:: steadystate_check_interval=time, ss_interval=time
+
+ The values during the rolling window will be collected with a period of
+ this value. If :option:`ss_interval` is 30s and :option:`ss_dur` is
+ 300s, 10 measurements will be taken. Default is 1s but that might not
+ converge, especially for slower devices, so set this accordingly. When
+ the unit is omitted, the value is interpreted in seconds.
+
Measurements and reporting
~~~~~~~~~~~~~~~~~~~~~~~~~~
It is the sum of submission and completion latency.
**bw**
- Bandwidth statistics based on samples. Same names as the xlat stats,
- but also includes the number of samples taken (**samples**) and an
- approximate percentage of total aggregate bandwidth this thread
- received in its group (**per**). This last value is only really
- useful if the threads in this group are on the same disk, since they
- are then competing for disk access.
+ Bandwidth statistics based on measurements from discrete
+ intervals. Fio continuously monitors bytes transferred and I/O
+ operations completed. By default fio calculates bandwidth in
+ each half-second interval (see :option:`bwavgtime`) and reports
+ descriptive statistics for the measurements here. Same names as
+ the xlat stats, but also includes the number of samples taken
+ (**samples**) and an approximate percentage of total aggregate
+ bandwidth this thread received in its group (**per**). This
+ last value is only really useful if the threads in this group
+ are on the same disk, since they are then competing for disk
+ access.
**iops**
- IOPS statistics based on samples. Same names as bw.
+ IOPS statistics based on measurements from discrete intervals.
+ For details see the description for bw above. See
+ :option:`iopsavgtime` to control the duration of the intervals.
+ Same values reported here as for bw except for percentage.
**lat (nsec/usec/msec)**
The distribution of I/O completion latencies. This is the time from when
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