-May not be available on all supported platforms. 'keep' is only
-available on Linux. If using ZFS on Solaris this must be set to 'none'
-because ZFS doesn't support it. Default: 'posix'.
-.RE
-.TP
-.BI fadvise_hint \fR=\fPbool
-Use \fBposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
-are likely to be issued. Default: true.
-.TP
-.BI fadvise_stream \fR=\fPint
-Use \fBposix_fadvise\fR\|(2) to advise the kernel what stream ID the
-writes issued belong to. Only supported on Linux. Note, this option
-may change going forward.
-.TP
-.BI size \fR=\fPint
-Total size of I/O for this job. \fBfio\fR will run until this many bytes have
-been transferred, unless limited by other options (\fBruntime\fR, for instance,
-or increased/descreased by \fBio_size\fR). Unless \fBnrfiles\fR and
-\fBfilesize\fR options are given, this amount will be divided between the
-available files for the job. If not set, fio will use the full size of the
-given files or devices. If the files do not exist, size must be given. It is
-also possible to give size as a percentage between 1 and 100. If size=20% is
-given, fio will use 20% of the full size of the given files or devices.
-.TP
-.BI io_size \fR=\fPint "\fR,\fB io_limit \fR=\fPint
-Normally fio operates within the region set by \fBsize\fR, which means that
-the \fBsize\fR option sets both the region and size of IO to be performed.
-Sometimes that is not what you want. With this option, it is possible to
-define just the amount of IO that fio should do. For instance, if \fBsize\fR
-is set to 20G and \fBio_limit\fR is set to 5G, fio will perform IO within
-the first 20G but exit when 5G have been done. The opposite is also
-possible - if \fBsize\fR is set to 20G, and \fBio_size\fR is set to 40G, then
-fio will do 40G of IO within the 0..20G region.
-.TP
-.BI fill_device \fR=\fPbool "\fR,\fB fill_fs" \fR=\fPbool
-Sets size to something really large and waits for ENOSPC (no space left on
-device) as the terminating condition. Only makes sense with sequential write.
-For a read workload, the mount point will be filled first then IO started on
-the result. This option doesn't make sense if operating on a raw device node,
-since the size of that is already known by the file system. Additionally,
-writing beyond end-of-device will not return ENOSPC there.
-.TP
-.BI filesize \fR=\fPirange
-Individual file sizes. May be a range, in which case \fBfio\fR will select sizes
-for files at random within the given range, limited to \fBsize\fR in total (if
-that is given). If \fBfilesize\fR is not specified, each created file is the
-same size.
-.TP
-.BI file_append \fR=\fPbool
-Perform IO after the end of the file. Normally fio will operate within the
-size of a file. If this option is set, then fio will append to the file
-instead. This has identical behavior to setting \fRoffset\fP to the size
-of a file. This option is ignored on non-regular files.
-.TP
-.BI blocksize \fR=\fPint[,int] "\fR,\fB bs" \fR=\fPint[,int]
-Block size for I/O units. Default: 4k. Values for reads, writes, and trims
-can be specified separately in the format \fIread\fR,\fIwrite\fR,\fItrim\fR
-either of which may be empty to leave that value at its default. If a trailing
-comma isn't given, the remainder will inherit the last value set.
-.TP
-.BI blocksize_range \fR=\fPirange[,irange] "\fR,\fB bsrange" \fR=\fPirange[,irange]
-Specify a range of I/O block sizes. The issued I/O unit will always be a
-multiple of the minimum size, unless \fBblocksize_unaligned\fR is set. Applies
-to both reads and writes if only one range is given, but can be specified
-separately with a comma separating the values. Example: bsrange=1k-4k,2k-8k.
-Also (see \fBblocksize\fR).
-.TP
-.BI bssplit \fR=\fPstr
-This option allows even finer grained control of the block sizes issued,
-not just even splits between them. With this option, you can weight various
-block sizes for exact control of the issued IO for a job that has mixed
-block sizes. The format of the option is bssplit=blocksize/percentage,
-optionally adding as many definitions as needed separated by a colon.
-Example: bssplit=4k/10:64k/50:32k/40 would issue 50% 64k blocks, 10% 4k
-blocks and 40% 32k blocks. \fBbssplit\fR also supports giving separate
-splits to reads and writes. The format is identical to what the
-\fBbs\fR option accepts, the read and write parts are separated with a
-comma.
-.TP
-.B blocksize_unaligned\fR,\fP bs_unaligned
-If set, any size in \fBblocksize_range\fR may be used. This typically won't
-work with direct I/O, as that normally requires sector alignment.
-.TP
-.BI blockalign \fR=\fPint[,int] "\fR,\fB ba" \fR=\fPint[,int]
-At what boundary to align random IO offsets. Defaults to the same as 'blocksize'
-the minimum blocksize given. Minimum alignment is typically 512b
-for using direct IO, though it usually depends on the hardware block size.
-This option is mutually exclusive with using a random map for files, so it
-will turn off that option.
-.TP
-.BI bs_is_seq_rand \fR=\fPbool
-If this option is set, fio will use the normal read,write blocksize settings as
-sequential,random instead. Any random read or write will use the WRITE
-blocksize settings, and any sequential read or write will use the READ
-blocksize setting.
-.TP
-.B zero_buffers
-Initialize buffers with all zeros. Default: fill buffers with random data.
-.TP
-.B refill_buffers
-If this option is given, fio will refill the IO buffers on every submit. The
-default is to only fill it at init time and reuse that data. Only makes sense
-if zero_buffers isn't specified, naturally. If data verification is enabled,
-refill_buffers is also automatically enabled.
-.TP
-.BI scramble_buffers \fR=\fPbool
-If \fBrefill_buffers\fR is too costly and the target is using data
-deduplication, then setting this option will slightly modify the IO buffer
-contents to defeat normal de-dupe attempts. This is not enough to defeat
-more clever block compression attempts, but it will stop naive dedupe
-of blocks. Default: true.
-.TP
-.BI buffer_compress_percentage \fR=\fPint
-If this is set, then fio will attempt to provide IO buffer content (on WRITEs)
-that compress to the specified level. Fio does this by providing a mix of
-random data and a fixed pattern. The fixed pattern is either zeroes, 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. Note
-that this is per block size unit, for file/disk wide compression level that
-matches this setting, you'll also want to set refill_buffers.
-.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 IO buffer.
-.TP
-.BI buffer_pattern \fR=\fPstr
-If set, fio will fill the IO buffers with this pattern. If not set, the contents
-of IO buffers is defined by the other options related to buffer contents. The
-setting can be any pattern of bytes, and can be prefixed with 0x for hex
-values. It may also be a string, where the string must then be wrapped with
-"", e.g.:
-.RS
-.RS
-\fBbuffer_pattern\fR="abcd"
-.RS
-or
-.RE
-\fBbuffer_pattern\fR=-12
-.RS
-or
-.RE
-\fBbuffer_pattern\fR=0xdeadface
-.RE
-.LP
-Also you can combine everything together in any order:
-.LP
-.RS
-\fBbuffer_pattern\fR=0xdeadface"abcd"-12
-.RE