calls will be excluded from other uses. Fio will manually clear it from the
CPU mask of other jobs.
+.. option:: job_start_clock_id=int
+ The clock_id passed to the call to `clock_gettime` used to record job_start
+ in the `json` output format. Default is 0, or CLOCK_REALTIME.
+
Target file/device
~~~~~~~~~~~~~~~~~~
reads and writes. See :manpage:`ionice(1)`. See also the
:option:`prioclass` option.
+.. option:: cmdprio_hint=int[,int] : [io_uring] [libaio]
+
+ Set the I/O priority hint to use for I/Os that must be issued with
+ a priority when :option:`cmdprio_percentage` or
+ :option:`cmdprio_bssplit` is set. If not specified when
+ :option:`cmdprio_percentage` or :option:`cmdprio_bssplit` is set,
+ this defaults to 0 (no hint). A single value applies to reads and
+ writes. Comma-separated values may be specified for reads and writes.
+ See also the :option:`priohint` option.
+
.. option:: cmdprio=int[,int] : [io_uring] [libaio]
Set the I/O priority value to use for I/Os that must be issued with
cmdprio_bssplit=blocksize/percentage:blocksize/percentage
- In this case, each entry will use the priority class and priority
- level defined by the options :option:`cmdprio_class` and
- :option:`cmdprio` respectively.
+ In this case, each entry will use the priority class, priority hint
+ and priority level defined by the options :option:`cmdprio_class`,
+ :option:`cmdprio` and :option:`cmdprio_hint` respectively.
The second accepted format for this option is:
accepted format does not restrict all entries to have the same priority
class and priority level.
- For both formats, only the read and write data directions are supported,
+ The third accepted format for this option is:
+
+ cmdprio_bssplit=blocksize/percentage/class/level/hint:...
+
+ This is an extension of the second accepted format that allows to also
+ specify a priority hint.
+
+ For all formats, only the read and write data directions are supported,
values for trim IOs are ignored. This option is mutually exclusive with
the :option:`cmdprio_percentage` option.
want fio to use placement identifier only at indices 0, 2 and 5 specify
``fdp_pli=0,2,5``.
+.. option:: md_per_io_size=int : [io_uring_cmd]
+
+ Size in bytes for separate metadata buffer per IO. Default: 0.
+
+.. option:: pi_act=int : [io_uring_cmd]
+
+ Action to take when nvme namespace is formatted with protection
+ information. If this is set to 1 and namespace is formatted with
+ metadata size equal to protection information size, fio won't use
+ separate metadata buffer or extended logical block. If this is set to
+ 1 and namespace is formatted with metadata size greater than protection
+ information size, fio will not generate or verify the protection
+ information portion of metadata for write or read case respectively.
+ If this is set to 0, fio generates protection information for
+ write case and verifies for read case. Default: 1.
+
+.. option:: pi_chk=str[,str][,str] : [io_uring_cmd]
+
+ Controls the protection information check. This can take one or more
+ of these values. Default: none.
+
+ **GUARD**
+ Enables protection information checking of guard field.
+ **REFTAG**
+ Enables protection information checking of logical block
+ reference tag field.
+ **APPTAG**
+ Enables protection information checking of application tag field.
+
+.. option:: apptag=int : [io_uring_cmd]
+
+ Specifies logical block application tag value, if namespace is
+ formatted to use end to end protection information. Default: 0x1234.
+
+.. option:: apptag_mask=int : [io_uring_cmd]
+
+ Specifies logical block application tag mask value, if namespace is
+ formatted to use end to end protection information. Default: 0xffff.
+
.. option:: cpuload=int : [cpuio]
Attempt to use the specified percentage of CPU cycles. This is a mandatory
priority setting, see I/O engine specific :option:`cmdprio_percentage`
and :option:`cmdprio_class` options.
+.. option:: priohint=int
+
+ Set the I/O priority hint. This is only applicable to platforms that
+ support I/O priority classes and to devices with features controlled
+ through priority hints, e.g. block devices supporting command duration
+ limits, or CDL. CDL is a way to indicate the desired maximum latency
+ of I/Os so that the device can optimize its internal command scheduling
+ according to the latency limits indicated by the user.
+
+ For per-I/O priority hint setting, see the I/O engine specific
+ :option:`cmdprio_hint` option.
+
.. option:: cpus_allowed=str
Controls the same options as :option:`cpumask`, but accepts a textual
same reporting group, unless if separated by a :option:`stonewall`, or by
using :option:`new_group`.
+ NOTE: When :option: `group_reporting` is used along with `json` output,
+ there are certain per-job properties which can be different between jobs
+ but do not have a natural group-level equivalent. Examples include
+ `kb_base`, `unit_base`, `sig_figs`, `thread_number`, `pid`, and
+ `job_start`. For these properties, the values for the first job are
+ recorded for the group.
+
.. option:: new_group
Start a new reporting group. See: :option:`group_reporting`. If not given,
.. option:: log_unix_epoch=bool
- If set, fio will log Unix timestamps to the log files produced by enabling
- write_type_log for each log type, instead of the default zero-based
- timestamps.
+ Backwards compatible alias for log_alternate_epoch.
.. option:: log_alternate_epoch=bool
.. option:: log_alternate_epoch_clock_id=int
- Specifies the clock_id to be used by clock_gettime to obtain the alternate epoch
- if either log_unix_epoch or log_alternate_epoch are true. Otherwise has no
- effect. Default value is 0, or CLOCK_REALTIME.
+ Specifies the clock_id to be used by clock_gettime to obtain the alternate
+ epoch if log_alternate_epoch is true. Otherwise has no effect. Default
+ value is 0, or CLOCK_REALTIME.
.. option:: block_error_percentiles=bool
server. The `server` string follows the same format as it does on the server
side, to allow IP/hostname/socket and port strings.
+Note that all job options must be defined in job files when running fio as a
+client. Any job options specified in `remote-args` will be ignored.
+
Fio can connect to multiple servers this way::
fio --client=<server1> <job file(s)> --client=<server2> <job file(s)>