85% of the CPU. In case of SMP machines,
use numjobs=<no_of_cpu> to get desired CPU
usage, as the cpuload only loads a single
- CPU at the desired rate.
+ CPU at the desired rate. A job never finishes
+ unless there is at least one non-cpuio job.
guasi The GUASI IO engine is the Generic Userspace
Asyncronous Syscall Interface approach
nice=int Run the job with the given nice value. See man nice(2).
+ On Windows, values less than -15 set the process class to "High";
+ -1 through -15 set "Above Normal"; 1 through 15 "Below Normal";
+ and above 15 "Idle" priority class.
+
prio=int Set the io priority value of this job. Linux limits us to
a positive value between 0 and 7, with 0 being the highest.
See man ionice(1). Refer to an appropriate manpage for
one cpu per job. If not enough CPUs are given for the jobs
listed, then fio will roundrobin the CPUs in the set.
-numa_cpu_nodes=str Set this job running on spcified NUMA nodes' CPUs. The
+numa_cpu_nodes=str Set this job running on specified NUMA nodes' CPUs. The
arguments allow comma delimited list of cpu numbers,
A-B ranges, or 'all'. Note, to enable numa options support,
fio must be built on a system with libnuma-dev(el) installed.
through 'write_iops_log', then the minimum of this option and
'log_avg_msec' will be used. Default: 500ms.
-create_serialize=bool If true, serialize the file creating for the jobs.
+create_serialize=bool If true, serialize the file creation for the jobs.
This may be handy to avoid interleaving of data
files, which may greatly depend on the filesystem
used and even the number of processors in the system.
runs of that job would then waste time recreating the file
set again and again.
+unlink_each_loop=bool Unlink job files after each iteration or loop.
+
loops=int Run the specified number of iterations of this job. Used
to repeat the same workload a given number of times. Defaults
to 1.
The actual log names will be foo_slat.x.log, foo_clat.x.log,
and foo_lat.x.log, where x is the index of the job (1..N,
where N is the number of jobs). This helps fio_generate_plot
- fine the logs automatically. If 'per_job_logs' is false, then
+ find the logs automatically. If 'per_job_logs' is false, then
the filename will not include the job index. See 'Log File
Formats'.
+write_hist_log=str Same as write_lat_log, but writes I/O completion
+ latency histograms. If no filename is given with this option, the
+ default filename of "jobname_clat_hist.x.log" is used, where x is
+ the index of the job (1..N, where N is the number of jobs). Even
+ if the filename is given, fio will still append the type of log.
+ If per_job_logs is false, then the filename will not include the
+ job index. See 'Log File Formats'.
+
write_iops_log=str Same as write_bw_log, but writes IOPS. If no filename is
given with this option, the default filename of
"jobname_type.x.log" is used,where x is the index of the job
specified period of time, reducing the resolution of the log.
See log_max_value as well. Defaults to 0, logging all entries.
+log_hist_msec=int Same as log_avg_msec, but logs entries for completion
+ latency histograms. Computing latency percentiles from averages of
+ intervals using log_avg_msec is innacurate. Setting this option makes
+ fio log histogram entries over the specified period of time, reducing
+ log sizes for high IOPS devices while retaining percentile accuracy.
+ See log_hist_coarseness as well. Defaults to 0, meaning histogram
+ logging is disabled.
+
+log_hist_coarseness=int Integer ranging from 0 to 6, defining the coarseness
+ of the resolution of the histogram logs enabled with log_hist_msec. For
+ each increment in coarseness, fio outputs half as many bins. Defaults to
+ 0, for which histogram logs contain 1216 latency bins. See
+ 'Log File Formats'.
+
log_max_value=bool If log_avg_msec is set, fio logs the average over that
window. If you instead want to log the maximum value, set this
option to 1. Defaults to 0, meaning that averaged values are
the --inflate-log command line parameter. The files will be
stored with a .fz suffix.
+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.
+
block_error_percentiles=bool If set, record errors in trim block-sized
units from writes and trims and output a histogram of
how many trims it took to get to errors, and what kind
[psyncv2] hipri Set RWF_HIPRI on IO, indicating to the kernel that
it's of higher priority than normal.
-[cpu] cpuload=int Attempt to use the specified percentage of CPU cycles.
+[cpuio] cpuload=int Attempt to use the specified percentage of CPU cycles.
-[cpu] cpuchunks=int Split the load into cycles of the given time. In
+[cpuio] cpuchunks=int Split the load into cycles of the given time. In
microseconds.
-[cpu] exit_on_io_done=bool Detect when IO threads are done, then exit.
+[cpuio] exit_on_io_done=bool Detect when IO threads are done, then exit.
[netsplice] hostname=str
[net] hostname=str The host name or IP address to use for TCP or UDP based IO.
[mtd] skip_bad=bool Skip operations against known bad blocks.
[libhdfs] hdfsdirectory libhdfs will create chunk in this HDFS directory
-[libhdfs] chunck_size the size of the chunck to use for each file.
+[libhdfs] chunk_size the size of the chunk to use for each file.
6.0 Interpreting the output
projects / fio.git / blobdiff