**$jobname**
The name of the worker thread or process.
+ **$clientuid**
+ IP of the fio process when using client/server mode.
**$jobnum**
The incremental number of the worker thread or process.
**$filenum**
limit reads or writes to a certain rate. If that is the case, then the
distribution may be skewed. Default: 50.
-.. option:: random_distribution=str:float[,str:float][,str:float]
+.. option:: random_distribution=str:float[:float][,str:float][,str:float]
By default, fio will use a completely uniform random distribution when asked
to perform random I/O. Sometimes it is useful to skew the distribution in
map. For the **normal** distribution, a normal (Gaussian) deviation is
supplied as a value between 0 and 100.
+ The second, optional float is allowed for **pareto**, **zipf** and **normal** distributions.
+ It allows to set base of distribution in non-default place, giving more control
+ over most probable outcome. This value is in range [0-1] which maps linearly to
+ range of possible random values.
+ Defaults are: random for **pareto** and **zipf**, and 0.5 for **normal**.
+ If you wanted to use **zipf** with a `theta` of 1.2 centered on 1/4 of allowed value range,
+ you would use ``random_distibution=zipf:1.2:0.25``.
+
For a **zoned** distribution, fio supports specifying percentages of I/O
access that should fall within what range of the file or device. For
example, given a criteria of:
**cpuio**
Doesn't transfer any data, but burns CPU cycles according to the
- :option:`cpuload` and :option:`cpuchunks` options. Setting
- :option:`cpuload`\=85 will cause that job to do nothing but burn 85%
+ :option:`cpuload`, :option:`cpuchunks` and :option:`cpumode` options.
+ Setting :option:`cpuload`\=85 will cause that job to do nothing but burn 85%
of the CPU. In case of SMP machines, use :option:`numjobs`\=<nr_of_cpu>
to get desired CPU usage, as the cpuload only loads a
single CPU at the desired rate. A job never finishes unless there is
at least one non-cpuio job.
+ Setting :option:`cpumode`\=qsort replace the default noop instructions loop
+ by a qsort algorithm to consume more energy.
**rdma**
The RDMA I/O engine supports both RDMA memory semantics
unless :option:`verify` is set or :option:`cuda_io` is `posix`.
:option:`iomem` must not be `cudamalloc`. This ioengine defines
engine specific options.
+ **dfs**
+ I/O engine supporting asynchronous read and write operations to the
+ DAOS File System (DFS) via libdfs.
I/O engine specific parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transferred to the device. The writefua option is ignored with this
selection.
+.. option:: hipri : [sg]
+
+ If this option is set, fio will attempt to use polled IO completions.
+ This will have a similar effect as (io_uring)hipri. Only SCSI READ and
+ WRITE commands will have the SGV4_FLAG_HIPRI set (not UNMAP (trim) nor
+ VERIFY). Older versions of the Linux sg driver that do not support
+ hipri will simply ignore this flag and do normal IO. The Linux SCSI
+ Low Level Driver (LLD) that "owns" the device also needs to support
+ hipri (also known as iopoll and mq_poll). The MegaRAID driver is an
+ example of a SCSI LLD. Default: clear (0) which does normal
+ (interrupted based) IO.
+
.. option:: http_host=str : [http]
Hostname to connect to. For S3, this could be the bucket hostname.
GPU to RAM before a write and copied from RAM to GPU after a
read. :option:`verify` does not affect use of cudaMemcpy.
+.. option:: pool=str : [dfs]
+
+ Specify the UUID of the DAOS pool to connect to.
+
+.. option:: cont=str : [dfs]
+
+ Specify the UUID of the DAOS container to open.
+
+.. option:: chunk_size=int : [dfs]
+
+ Specificy a different chunk size (in bytes) for the dfs file.
+ Use DAOS container's chunk size by default.
+
+.. option:: object_class=str : [dfs]
+
+ Specificy a different object class for the dfs file.
+ Use DAOS container's object class by default.
+
I/O depth
~~~~~~~~~
before we have to complete it and do our :option:`thinktime`. In other words, this
setting effectively caps the queue depth if the latter is larger.
+.. option:: thinktime_blocks_type=str
+
+ Only valid if :option:`thinktime` is set - control how :option:`thinktime_blocks`
+ triggers. The default is `complete`, which triggers thinktime when fio completes
+ :option:`thinktime_blocks` blocks. If this is set to `issue`, then the trigger happens
+ at the issue side.
+
.. option:: rate=int[,int][,int]
Cap the bandwidth used by this job. The number is in bytes/sec, the normal
true, fio will continue running and try to meet :option:`latency_target`
by adjusting queue depth.
-.. option:: max_latency=time
+.. option:: max_latency=time[,time][,time]
If set, fio will exit the job with an ETIMEDOUT error if it exceeds this
maximum latency. When the unit is omitted, the value is interpreted in
- microseconds.
+ microseconds. Comma-separated values may be specified for reads, writes,
+ and trims as described in :option:`blocksize`.
.. option:: rate_cycle=int
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