.I int
Integer. A whole number value, which may contain an integer prefix
and an integer suffix.
-
+.RS
+.RS
+.P
[*integer prefix*] **number** [*integer suffix*]
-
+.RE
+.P
The optional *integer prefix* specifies the number's base. The default
is decimal. *0x* specifies hexadecimal.
-
+.P
The optional *integer suffix* specifies the number's units, and includes an
optional unit prefix and an optional unit. For quantities of data, the
default unit is bytes. For quantities of time, the default unit is seconds
unless otherwise specified.
-
-With \fBkb_base=1000\fR, fio follows international standards for unit
+.P
+With `kb_base=1000', fio follows international standards for unit
prefixes. To specify power-of-10 decimal values defined in the
International System of Units (SI):
-
-.nf
+.RS
+.P
ki means kilo (K) or 1000
+.RE
+.RS
mi means mega (M) or 1000**2
+.RE
+.RS
gi means giga (G) or 1000**3
+.RE
+.RS
ti means tera (T) or 1000**4
+.RE
+.RS
pi means peta (P) or 1000**5
-.fi
-
+.RE
+.P
To specify power-of-2 binary values defined in IEC 80000-13:
-
-.nf
+.RS
+.P
k means kibi (Ki) or 1024
+.RE
+.RS
m means mebi (Mi) or 1024**2
+.RE
+.RS
g means gibi (Gi) or 1024**3
+.RE
+.RS
t means tebi (Ti) or 1024**4
+.RE
+.RS
p means pebi (Pi) or 1024**5
-.fi
-
-With \fBkb_base=1024\fR (the default), the unit prefixes are opposite
+.RE
+.P
+With `kb_base=1024' (the default), the unit prefixes are opposite
from those specified in the SI and IEC 80000-13 standards to provide
compatibility with old scripts. For example, 4k means 4096.
-
+.P
For quantities of data, an optional unit of 'B' may be included
(e.g., 'kB' is the same as 'k').
-
+.P
The *integer suffix* is not case sensitive (e.g., m/mi mean mebi/mega,
not milli). 'b' and 'B' both mean byte, not bit.
-
-Examples with \fBkb_base=1000\fR:
-
-.nf
+.P
+Examples with `kb_base=1000':
+.RS
+.P
4 KiB: 4096, 4096b, 4096B, 4k, 4kb, 4kB, 4K, 4KB
+.RE
+.RS
1 MiB: 1048576, 1m, 1024k
+.RE
+.RS
1 MB: 1000000, 1mi, 1000ki
+.RE
+.RS
1 TiB: 1073741824, 1t, 1024m, 1048576k
+.RE
+.RS
1 TB: 1000000000, 1ti, 1000mi, 1000000ki
-.fi
-
-Examples with \fBkb_base=1024\fR (default):
-
-.nf
+.RE
+.P
+Examples with `kb_base=1024' (default):
+.RS
+.P
4 KiB: 4096, 4096b, 4096B, 4k, 4kb, 4kB, 4K, 4KB
+.RE
+.RS
1 MiB: 1048576, 1m, 1024k
+.RE
+.RS
1 MB: 1000000, 1mi, 1000ki
+.RE
+.RS
1 TiB: 1073741824, 1t, 1024m, 1048576k
+.RE
+.RS
1 TB: 1000000000, 1ti, 1000mi, 1000000ki
-.fi
-
+.RE
+.P
To specify times (units are not case sensitive):
-
-.nf
+.RS
+.P
D means days
+.RE
+.RS
H means hours
+.RE
+.RS
M mean minutes
+.RE
+.RS
s or sec means seconds (default)
+.RE
+.RS
ms or msec means milliseconds
+.RE
+.RS
us or usec means microseconds
-.fi
-
+.RE
+.P
If the option accepts an upper and lower range, use a colon ':' or
minus '-' to separate such values. See `irange` parameter type.
If the lower value specified happens to be larger than the upper value
the two values are swapped.
+.RE
.TP
.I bool
Boolean. Usually parsed as an integer, however only defined for
Fio defaults to read if the option is not specified.
For mixed I/O, the default split is 50/50. For certain types of io the result
may still be skewed a bit, since the speed may be different. It is possible to
-specify a number of IO's to do before getting a new offset, this is done by
+specify a number of IOs to do before getting a new offset, this is done by
appending a `:\fI<nr>\fR to the end of the string given. For a random read, it
would look like \fBrw=randread:8\fR for passing in an offset modifier with a
value of 8. If the postfix is used with a sequential IO pattern, then the value
.P
\fBsequential\fR is only useful for random IO, where fio would normally
generate a new random offset for every IO. If you append eg 8 to randread, you
-would get a new random offset for every 8 IO's. The result would be a seek for
-only every 8 IO's, instead of for every IO. Use \fBrw=randread:8\fR to specify
+would get a new random offset for every 8 IOs. The result would be a seek for
+only every 8 IOs, instead of for every IO. Use \fBrw=randread:8\fR to specify
that. As sequential IO is already sequential, setting \fBsequential\fR for that
would not result in any differences. \fBidentical\fR behaves in a similar
fashion, except it sends the same offset 8 number of times before generating a
.B exitall
Terminate all jobs when one finishes. Default: wait for each job to finish.
.TP
-.B exitall_on_error \fR=\fPbool
+.B exitall_on_error
Terminate all jobs if one job finishes in error. Default: wait for each job
to finish.
.TP
Specifies the number of iterations (runs of the same workload) of this job.
Default: 1.
.TP
-.BI verify_only \fR=\fPbool
+.BI verify_only
Do not perform the specified workload, only verify data still matches previous
invocation of this workload. This option allows one to check data multiple
times at a later date without overwriting it. This option makes sense only for
Replay the I/O patterns contained in the specified file generated by
\fBwrite_iolog\fR, or may be a \fBblktrace\fR binary file.
.TP
-.BI replay_no_stall \fR=\fPint
+.BI replay_no_stall \fR=\fPbool
While replaying I/O patterns using \fBread_iolog\fR the default behavior
attempts to respect timing information between I/Os. Enabling
\fBreplay_no_stall\fR causes I/Os to be replayed as fast as possible while
Set RWF_HIPRI on IO, indicating to the kernel that it's of
higher priority than normal.
.TP
+.BI (pvsync2)hipri_percentage
+When hipri is set this determines the probability of a pvsync2 IO being high
+priority. The default is 100%.
+.TP
.BI (net,netsplice)hostname \fR=\fPstr
The host name or IP address to use for TCP or UDP based IO.
If the job is a TCP listener or UDP reader, the hostname is not
connections rather than initiating an outgoing connection. The
hostname must be omitted if this option is used.
.TP
-.BI (net,netsplice)pingpong \fR=\fPbool
+.BI (net,netsplice)pingpong
Normally a network writer will just continue writing data, and a network reader
will just consume packets. If pingpong=1 is set, a writer will send its normal
payload to the reader, then wait for the reader to send the same payload back.
cluster. If the clustername is specified, the clientname shall be the full
type.id string. If no type. prefix is given, fio will add 'client.' by default.
.TP
-.BI (mtd)skipbad \fR=\fPbool
+.BI (mtd)skip_bad \fR=\fPbool
Skip operations against known bad blocks.
.SH OUTPUT
While running, \fBfio\fR will display the status of the created jobs. For
Number of I/Os performed by all groups.
.TP
.B merge
-Number of merges in the I/O scheduler.
+Number of merges performed by the I/O scheduler.
.TP
.B ticks
Number of ticks we kept the disk busy.
terse_version_3;fio_version;jobname;groupid;error;read_kb;read_bandwidth;read_iops;read_runtime_ms;read_slat_min;read_slat_max;read_slat_mean;read_slat_dev;read_clat_max;read_clat_min;read_clat_mean;read_clat_dev;read_clat_pct01;read_clat_pct02;read_clat_pct03;read_clat_pct04;read_clat_pct05;read_clat_pct06;read_clat_pct07;read_clat_pct08;read_clat_pct09;read_clat_pct10;read_clat_pct11;read_clat_pct12;read_clat_pct13;read_clat_pct14;read_clat_pct15;read_clat_pct16;read_clat_pct17;read_clat_pct18;read_clat_pct19;read_clat_pct20;read_tlat_min;read_lat_max;read_lat_mean;read_lat_dev;read_bw_min;read_bw_max;read_bw_agg_pct;read_bw_mean;read_bw_dev;write_kb;write_bandwidth;write_iops;write_runtime_ms;write_slat_min;write_slat_max;write_slat_mean;write_slat_dev;write_clat_max;write_clat_min;write_clat_mean;write_clat_dev;write_clat_pct01;write_clat_pct02;write_clat_pct03;write_clat_pct04;write_clat_pct05;write_clat_pct06;write_clat_pct07;write_clat_pct08;write_clat_pct09;write_clat_pct10;write_clat_pct11;write_clat_pct12;write_clat_pct13;write_clat_pct14;write_clat_pct15;write_clat_pct16;write_clat_pct17;write_clat_pct18;write_clat_pct19;write_clat_pct20;write_tlat_min;write_lat_max;write_lat_mean;write_lat_dev;write_bw_min;write_bw_max;write_bw_agg_pct;write_bw_mean;write_bw_dev;cpu_user;cpu_sys;cpu_csw;cpu_mjf;pu_minf;iodepth_1;iodepth_2;iodepth_4;iodepth_8;iodepth_16;iodepth_32;iodepth_64;lat_2us;lat_4us;lat_10us;lat_20us;lat_50us;lat_100us;lat_250us;lat_500us;lat_750us;lat_1000us;lat_2ms;lat_4ms;lat_10ms;lat_20ms;lat_50ms;lat_100ms;lat_250ms;lat_500ms;lat_750ms;lat_1000ms;lat_2000ms;lat_over_2000ms;disk_name;disk_read_iops;disk_write_iops;disk_read_merges;disk_write_merges;disk_read_ticks;write_ticks;disk_queue_time;disk_util
.fi
.RE
+.SH JSON+ OUTPUT
+The \fBjson+\fR output format is identical to the \fBjson\fR output format except that it
+adds a full dump of the completion latency bins. Each \fBbins\fR object contains a
+set of (key, value) pairs where keys are latency durations and values count how
+many I/Os had completion latencies of the corresponding duration. For example,
+consider:
+
+.RS
+"bins" : { "87552" : 1, "89600" : 1, "94720" : 1, "96768" : 1, "97792" : 1, "99840" : 1, "100864" : 2, "103936" : 6, "104960" : 534, "105984" : 5995, "107008" : 7529, ... }
+.RE
+
+This data indicates that one I/O required 87,552ns to complete, two I/Os required
+100,864ns to complete, and 7529 I/Os required 107,008ns to complete.
+
+Also included with fio is a Python script \fBfio_jsonplus_clat2csv\fR that takes
+json+ output and generates CSV-formatted latency data suitable for plotting.
+
+The latency durations actually represent the midpoints of latency intervals.
+For details refer to stat.h.
+
+
.SH TRACE FILE FORMAT
There are two trace file format that you can encounter. The older (v1) format
is unsupported since version 1.20-rc3 (March 2008). It will still be described
projects / fio.git / blobdiff