.B external
Loads an external I/O engine object file. Append the engine filename as
`:\fIenginepath\fR'.
+.TP
+.B falloc
+ IO engine that does regular linux native fallocate callt to simulate data
+transfer as fio ioengine
+.br
+ DDIR_READ does fallocate(,mode = FALLOC_FL_KEEP_SIZE,)
+.br
+ DIR_WRITE does fallocate(,mode = 0)
+.br
+ DDIR_TRIM does fallocate(,mode = FALLOC_FL_KEEP_SIZE|FALLOC_FL_PUNCH_HOLE)
+.TP
+.B e4defrag
+IO engine that does regular EXT4_IOC_MOVE_EXT ioctls to simulate defragment activity
+request to DDIR_WRITE event
.RE
+.P
.RE
.TP
.BI iodepth \fR=\fPint
asked to limit reads or writes to a certain rate. If that is the case, then
the distribution may be skewed. Default: 50.
.TP
+.BI random_distribution \fR=\fPstr: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:
+.RS
+.TP
+.B random
+Uniform random distribution
+.TP
+.B zipf
+Zipf distribution
+.TP
+.B pareto
+Pareto distribution
+.TP
+.RE
+.P
+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.
+.TP
.B norandommap
Normally \fBfio\fR will cover every block of the file when doing random I/O. If
this parameter is given, a new offset will be chosen without looking at past
random block map. As coverage will not be as complete as with random maps, this
option is disabled by default.
.TP
+.BI random_generator \fR=\fPstr
+Fio supports the following engines for generating IO offsets for random IO:
+.RS
+.TP
+.B tausworthe
+Strong 2^88 cycle random number generator
+.TP
+.B lfsr
+Linear feedback shift register generator
+.TP
+.RE
+.P
+Tausworthe is a strong random number generator, but it requires tracking on the
+side if we want to ensure that blocks are only read or written once. LFSR
+guarantees that we never generate the same offset twice, and it's also less
+computationally expensive. It's not a true random generator, however, though
+for IO purposes it's typically good enough. LFSR only works with single block
+sizes, not with workloads that use multiple block sizes. If used with such a
+workload, fio may read or write some blocks multiple times.
+.TP
.BI nice \fR=\fPint
Run job with given nice value. See \fInice\fR\|(2).
.TP
Average bandwidth for \fBrate\fR and \fBratemin\fR over this number of
milliseconds. Default: 1000ms.
.TP
+.BI max_latency \fR=\fPint
+If set, fio will exit the job if it exceeds this maximum latency. It will exit
+with an ETIME error.
+.TP
.BI cpumask \fR=\fPint
Set CPU affinity for this job. \fIint\fR is a bitmask of allowed CPUs the job
may run on. See \fBsched_setaffinity\fR\|(2).
.BI cpus_allowed \fR=\fPstr
Same as \fBcpumask\fR, but allows a comma-delimited list of CPU numbers.
.TP
+.BI numa_cpu_nodes \fR=\fPstr
+Set this job running on spcified NUMA nodes' CPUs. The arguments allow
+comma delimited list of cpu numbers, A-B ranges, or 'all'.
+.TP
+.BI numa_mem_policy \fR=\fPstr
+Set this job's memory policy and corresponding NUMA nodes. Format of
+the argements:
+.RS
+.TP
+.B <mode>[:<nodelist>]
+.TP
+.B mode
+is one of the following memory policy:
+.TP
+.B default, prefer, bind, interleave, local
+.TP
+.RE
+For \fBdefault\fR and \fBlocal\fR memory policy, no \fBnodelist\fR is
+needed to be specified. For \fBprefer\fR, only one node is
+allowed. For \fBbind\fR and \fBinterleave\fR, \fBnodelist\fR allows
+comma delimited list of numbers, A-B ranges, or 'all'.
+.TP
.BI startdelay \fR=\fPint
Delay start of job for the specified number of seconds.
.TP
these time calls will be excluded from other uses. Fio will manually clear it
from the CPU mask of other jobs.
.TP
+.BI ignore_error \fR=\fPstr
+Sometimes you want to ignore some errors during test in that case you can specify
+error list for each error type.
+.br
+ignore_error=READ_ERR_LIST,WRITE_ERR_LIST,VERIFY_ERR_LIST
+.br
+errors for given error type is separated with ':'.
+Error may be symbol ('ENOSPC', 'ENOMEM') or an integer.
+.br
+Example: ignore_error=EAGAIN,ENOSPC:122 .
+.br
+This option will ignore EAGAIN from READ, and ENOSPC and 122(EDQUOT) from WRITE.
+.TP
+.BI error_dump \fR=\fPbool
+If set dump every error even if it is non fatal, true by default. If disabled
+only fatal error will be dumped
+.TP
.BI cgroup \fR=\fPstr
Add job to this control group. If it doesn't exist, it will be created.
The system must have a mounted cgroup blkio mount point for this to work. If
Transmission control protocol
.TP
.B udp
-Unreliable datagram protocol
+User datagram protocol
.TP
.B unix
UNIX domain socket
For TCP network connections, tell fio to listen for incoming
connections rather than initiating an outgoing connection. The
hostname must be omitted if this option is used.
+.TP
+.BI (e4defrag,donorname) \fR=\fPstr
+File will be used as a block donor (swap extents between files)
+.TP
+.BI (e4defrag,inplace) \fR=\fPint
+Configure donor file block allocation strategy
+.RS
+.BI 0(default) :
+Preallocate donor's file on init
+.TP
+.BI 1:
+allocate space immidietly inside defragment event, and free right after event
+.RE
+.TP
.SH OUTPUT
While running, \fBfio\fR will display the status of the created jobs. For
example:
projects / fio.git / blobdiff