if fio is asked to limit reads or writes to a certain rate.
If that is the case, then the distribution may be skewed.
+random_distribution=str:float By default, fio will use a completely uniform
+ random distribution when asked to perform random IO. Sometimes
+ it is useful to skew the distribution in specific ways,
+ ensuring that some parts of the data is more hot than others.
+ fio includes the following distribution models:
+
+ random Uniform random distribution
+ zipf Zipf distribution
+ pareto Pareto distribution
+
+ When using a zipf or pareto distribution, an input value
+ is also needed to define the access pattern. For zipf, this
+ is the zipf theta. For pareto, it's the pareto power. Fio
+ includes a test program, genzipf, that can be used visualize
+ what the given input values will yield in terms of hit rates.
+ If you wanted to use zipf with a theta of 1.2, you would use
+ random_distribution=zipf:1.2 as the option. If a non-uniform
+ model is used, fio will disable use of the random map.
+
norandommap Normally fio will cover every block of the file when doing
random IO. If this option is given, fio will just get a
new random offset without looking at past io history. This
the job to exit. The same format as rate is used for read vs
write seperation.
+max_latency=int If set, fio will exit the job if it exceeds this maximum
+ latency. It will exit with an ETIME error.
+
ratecycle=int Average bandwidth for 'rate' and 'ratemin' over this number
of milliseconds.
allows a range of CPUs. Say you wanted a binding to CPUs
1, 5, and 8-15, you would set cpus_allowed=1,5,8-15.
+numa_cpu_nodes=str Set this job running on spcified NUMA nodes' CPUs. The
+ arguments allow comma delimited list of cpu numbers,
+ A-B ranges, or 'all'. Note, to enable numa options support,
+ export the following environment variables,
+ export EXTFLAGS+=" -DFIO_HAVE_LIBNUMA "
+ export EXTLIBS+=" -lnuma "
+
+numa_mem_policy=str Set this job's memory policy and corresponding NUMA
+ nodes. Format of the argements:
+ <mode>[:<nodelist>]
+ `mode' is one of the following memory policy:
+ default, prefer, bind, interleave, local
+ For `default' and `local' memory policy, no node is
+ needed to be specified.
+ For `prefer', only one node is allowed.
+ For `bind' and `interleave', it allow comma delimited
+ list of numbers, A-B ranges, or 'all'.
+
startdelay=time Start this job the specified number of seconds after fio
has started. Only useful if the job file contains several
jobs, and you want to delay starting some jobs to a certain
conjunction with new_group.
group_reporting It may sometimes be interesting to display statistics for
- groups of jobs as a whole instead of for each individual job. This is
- especially true if 'numjobs' is used; looking at individual
- thread/process output quickly becomes unwieldy. To see the final report
- per-group instead of per-job, use 'group_reporting'. Jobs in a file
- will be part of the same reporting group, unless if separated by a
- stonewall, or by using 'new_group'.
+ groups of jobs as a whole instead of for each individual job.
+ This is especially true if 'numjobs' is used; looking at
+ individual thread/process output quickly becomes unwieldy.
+ To see the final report per-group instead of per-job, use
+ 'group_reporting'. Jobs in a file will be part of the same
+ reporting group, unless if separated by a stonewall, or by
+ using 'new_group'.
thread fio defaults to forking jobs, however if this option is
given, fio will use pthread_create(3) to create threads
---- ---
P Thread setup, but not started.
C Thread created.
-I Thread initialized, waiting.
+I Thread initialized, waiting or generating necessary data.
p Thread running pre-reading file(s).
R Running, doing sequential reads.
r Running, doing random reads.