.TP
.B zoned
Zoned random distribution
+.B zoned_abs
+Zoned absolute random distribution
.RE
.P
When using a \fBzipf\fR or \fBpareto\fR distribution, an input value is also
random_distribution=zoned:60/10:30/20:8/30:2/40
.RE
.P
-similarly to how \fBbssplit\fR works for setting ranges and percentages
+A \fBzoned_abs\fR distribution works exactly like the\fBzoned\fR, except that
+it takes absolute sizes. For example, let's say you wanted to define access
+according to the following criteria:
+.RS
+.P
+.PD 0
+60% of accesses should be to the first 20G
+.P
+30% of accesses should be to the next 100G
+.P
+10% of accesses should be to the next 500G
+.PD
+.RE
+.P
+we can define an absolute zoning distribution with:
+.RS
+.P
+random_distribution=zoned:60/10:30/20:8/30:2/40
+.RE
+.P
+Similarly to how \fBbssplit\fR works for setting ranges and percentages
of block sizes. Like \fBbssplit\fR, it's possible to specify separate
zones for reads, writes, and trims. If just one set is given, it'll apply to
all of them.
blocks. Default: true.
.TP
.BI buffer_compress_percentage \fR=\fPint
-If this is set, then fio will attempt to provide I/O buffer content (on
-WRITEs) that compresses to the specified level. Fio does this by providing a
-mix of random data and a fixed pattern. The fixed pattern is either zeros,
-or the pattern specified by \fBbuffer_pattern\fR. If the pattern option
-is used, it might skew the compression ratio slightly. Note that this is per
-block size unit, for file/disk wide compression level that matches this
-setting, you'll also want to set \fBrefill_buffers\fR.
+If this is set, then fio will attempt to provide I/O buffer content
+(on WRITEs) that compresses to the specified level. Fio does this by
+providing a mix of random data followed by fixed pattern data. The
+fixed pattern is either zeros, or the pattern specified by
+\fBbuffer_pattern\fR. If the \fBbuffer_pattern\fR option is used, it
+might skew the compression ratio slightly. Setting
+\fBbuffer_compress_percentage\fR to a value other than 100 will also
+enable \fBrefill_buffers\fR in order to reduce the likelihood that
+adjacent blocks are so similar that they over compress when seen
+together. See \fBbuffer_compress_chunk\fR for how to set a finer or
+coarser granularity of the random/fixed data regions. Defaults to unset
+i.e., buffer data will not adhere to any compression level.
.TP
.BI buffer_compress_chunk \fR=\fPint
-See \fBbuffer_compress_percentage\fR. This setting allows fio to manage
-how big the ranges of random data and zeroed data is. Without this set, fio
-will provide \fBbuffer_compress_percentage\fR of blocksize random data,
-followed by the remaining zeroed. With this set to some chunk size smaller
-than the block size, fio can alternate random and zeroed data throughout the
-I/O buffer.
+This setting allows fio to manage how big the random/fixed data region
+is when using \fBbuffer_compress_percentage\fR. When
+\fBbuffer_compress_chunk\fR is set to some non-zero value smaller than the
+block size, fio can repeat the random/fixed region throughout the I/O
+buffer at the specified interval (which particularly useful when
+bigger block sizes are used for a job). When set to 0, fio will use a
+chunk size that matches the block size resulting in a single
+random/fixed region within the I/O buffer. Defaults to 512. When the
+unit is omitted, the value is interpreted in bytes.
.TP
.BI buffer_pattern \fR=\fPstr
If set, fio will fill the I/O buffers with this pattern or with the contents
writing. These buffers will be naturally dedupable. The contents of the
buffers depend on what other buffer compression settings have been set. It's
possible to have the individual buffers either fully compressible, or not at
-all. This option only controls the distribution of unique buffers.
+all \-\- this option only controls the distribution of unique buffers. Setting
+this option will also enable \fBrefill_buffers\fR to prevent every buffer
+being identical.
.TP
.BI invalidate \fR=\fPbool
Invalidate the buffer/page cache parts of the files to be used prior to
.B rdma
The RDMA I/O engine supports both RDMA memory semantics
(RDMA_WRITE/RDMA_READ) and channel semantics (Send/Recv) for the
-InfiniBand, RoCE and iWARP protocols.
+InfiniBand, RoCE and iWARP protocols. This engine defines engine
+specific options.
.TP
.B falloc
I/O engine that does regular fallocate to simulate data transfer as
Simply create the files and do no I/O to them. You still need to set
\fBfilesize\fR so that all the accounting still occurs, but no actual I/O will be
done other than creating the file.
+.TP
+.B libpmem
+Read and write using mmap I/O to a file on a filesystem
+mounted with DAX on a persistent memory device through the NVML
+libpmem library.
.SS "I/O engine specific parameters"
In addition, there are some parameters which are only valid when a specific
\fBioengine\fR is in use. These are used identically to normal parameters,
this will be the starting port number since fio will use a range of
ports.
.TP
-.BI (netsplice,net)hostname \fR=\fPstr
-The hostname or IP address to use for TCP or UDP based I/O. If the job is
-a TCP listener or UDP reader, the hostname is not used and must be omitted
-unless it is a valid UDP multicast address.
+.BI (rdma)port
+The port to use for RDMA-CM communication. This should be the same
+value on the client and the server side.
+.TP
+.BI (netsplice,net, rdma)hostname \fR=\fPstr
+The hostname or IP address to use for TCP, UDP or RDMA-CM based I/O.
+If the job is a TCP listener or UDP reader, the hostname is not used
+and must be omitted unless it is a valid UDP multicast address.
.TP
.BI (netsplice,net)interface \fR=\fPstr
The IP address of the network interface used to send or receive UDP
.TP
.BI (libhdfs)chunk_size
The size of the chunk to use for each file.
+.TP
+.BI (rdma)verb \fR=\fPstr
+The RDMA verb to use on this side of the RDMA ioengine
+connection. Valid values are write, read, send and recv. These
+correspond to the equivalent RDMA verbs (e.g. write = rdma_write
+etc.). Note that this only needs to be specified on the client side of
+the connection. See the examples folder.
+.TP
+.BI (rdma)bindname \fR=\fPstr
+The name to use to bind the local RDMA-CM connection to a local RDMA
+device. This could be a hostname or an IPv4 or IPv6 address. On the
+server side this will be passed into the rdma_bind_addr() function and
+on the client site it will be used in the rdma_resolve_add()
+function. This can be useful when multiple paths exist between the
+client and the server or in certain loopback configurations.
.SS "I/O depth"
.TP
.BI iodepth \fR=\fPint
`\-\-percentile_list=99.5:99.9' will cause fio to report the values of
completion latency below which 99.5% and 99.9% of the observed latencies
fell, respectively.
+.TP
+.BI significant_figures \fR=\fPint
+If using \fB\-\-output\-format\fR of `normal', set the significant figures
+to this value. Higher values will yield more precise IOPS and throughput
+units, while lower values will round. Requires a minimum value of 1 and a
+maximum value of 10. Defaults to 4.
.SS "Error handling"
.TP
.BI exitall_on_error
.B I
Thread initialized, waiting or generating necessary data.
.TP
-.B P
+.B p
Thread running pre\-reading file(s).
.TP
.B /
projects / fio.git / blobdiff