of the value. Accepted suffixes are `k', 'M', 'G', 'T', and 'P', denoting
kilo (1024), mega (1024^2), giga (1024^3), tera (1024^4), and peta (1024^5)
respectively. The suffix is not case sensitive. If prefixed with '0x', the
-value is assumed to be base 16 (hexadecimal).
+value is assumed to be base 16 (hexadecimal). A suffix may include a trailing
+'b', for instance 'kb' is identical to 'k'. You can specify a base 10 value
+by using 'KiB', 'MiB', 'GiB', etc. This is useful for disk drives where
+values are often given in base 10 values. Specifying '30GiB' will get you
+30*1000^3 bytes.
.TP
.I bool
Boolean: a true or false value. `0' denotes false, `1' denotes true.
Seed the random number generator in a predictable way so results are repeatable
across runs. Default: true.
.TP
+.BI fallocate \fR=\fPbool
+By default, fio will use fallocate() to advise the system of the size of the
+file we are going to write. This can be turned off with fallocate=0. May not
+be available on all supported platforms.
+.TP
.BI fadvise_hint \fR=\fPbool
Disable use of \fIposix_fadvise\fR\|(2) to advise the kernel what I/O patterns
are likely to be issued. Default: true.
.TP
.BI blocksize \fR=\fPint[,int] "\fR,\fB bs" \fR=\fPint[,int]
Block size for I/O units. Default: 4k. Values for reads and writes can be
-specified seperately in the format \fIread\fR,\fIwrite\fR, either of
+specified separately in the format \fIread\fR,\fIwrite\fR, either of
which may be empty to leave that value at its default.
.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
-seperately with a comma seperating the values. Example: bsrange=1k-4k,2k-8k.
+separately with a comma seperating the values. Example: bsrange=1k-4k,2k-8k.
Also (see \fBblocksize\fR).
.TP
.BI bssplit \fR=\fPstr
Like \fBfsync\fR, but uses \fBfdatasync\fR\|(2) instead to only sync the
data parts of the file. Default: 0.
.TP
+.BI sync_file_range \fR=\fPstr:int
+Use sync_file_range() for every \fRval\fP number of write operations. Fio will
+track range of writes that have happened since the last sync_file_range() call.
+\fRstr\fP can currently be one or more of:
+.RS
+.TP
+.B wait_before
+SYNC_FILE_RANGE_WAIT_BEFORE
+.TP
+.B write
+SYNC_FILE_RANGE_WRITE
+.TP
+.B wait_after
+SYNC_FILE_RANGE_WRITE
+.TP
+.RE
+.P
+So if you do sync_file_range=wait_before,write:8, fio would use
+\fBSYNC_FILE_RANGE_WAIT_BEFORE | SYNC_FILE_RANGE_WRITE\fP for every 8 writes.
+Also see the sync_file_range(2) man page. This option is Linux specific.
+.TP
.BI overwrite \fR=\fPbool
If writing, setup the file first and do overwrites. Default: false.
.TP
.RS
.TP
.B md5 crc16 crc32 crc32c crc32c-intel crc64 crc7 sha256 sha512 sha1
-Store appropriate checksum in the header of each block.
+Store appropriate checksum in the header of each block. crc32c-intel is
+hardware accelerated SSE4.2 driven, falls back to regular crc32c if
+not supported by the system.
.TP
.B meta
Write extra information about each I/O (timestamp, block number, etc.). The
Tell fio to set the given CPU affinity on the async IO verification threads.
See \fBcpus_allowed\fP for the format used.
.TP
+.BI verify_backlog \fR=\fPint
+Fio will normally verify the written contents of a job that utilizes verify
+once that job has completed. In other words, everything is written then
+everything is read back and verified. You may want to verify continually
+instead for a variety of reasons. Fio stores the meta data associated with an
+IO block in memory, so for large verify workloads, quite a bit of memory would
+be used up holding this meta data. If this option is enabled, fio will verify
+the previously written blocks before continuing to write new ones.
+.TP
+.BI verify_backlog_batch \fR=\fPint
+Control how many blocks fio will verify if verify_backlog is set. If not set,
+will default to the value of \fBverify_backlog\fR (meaning the entire queue is
+read back and verified).
+.TP
.B stonewall
Wait for preceeding jobs in the job file to exit before starting this one.
\fBstonewall\fR implies \fBnew_group\fR.
these time calls will be excluded from other uses. Fio will manually clear it
from the CPU mask of other jobs.
.TP
-.BI cgroup_root \fR=\fPstr
-Root of the mounted blkio cgroup file systems. This is a Linux
-specific IO controller. If your system doesn't have it mounted,
-you can do so with:
-
-# mount -t cgroup -o blkio none /cgroup
-
-The cgroup_root defaults to /cgroup, if mounted elsewhere please specify this
-option.
-.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
+your system doesn't have it mounted, you can do so with:
+
+# mount -t cgroup -o blkio none /cgroup
.TP
.BI cgroup_weight \fR=\fPint
Set the weight of the cgroup to this value. See the documentation that comes
with the kernel, allowed values are in the range of 100..1000.
+.TP
+.BI cgroup_nodelete \fR=\fPbool
+Normally fio will delete the cgroups it has created after the job completion.
+To override this behavior and to leave cgroups around after the job completion,
+set cgroup_nodelete=1. This can be useful if one wants to inspect various
+cgroup files after job completion. Default: false
+.TP
+.BI uid \fR=\fPint
+Instead of running as the invoking user, set the user ID to this value before
+the thread/process does any work.
+.TP
+.BI gid \fR=\fPint
+Set group ID, see \fBuid\fR.
.SH OUTPUT
While running, \fBfio\fR will display the status of the created jobs. For
example:
.RE
.SH AUTHORS
.B fio
-was written by Jens Axboe <jens.axboe@oracle.com>.
+was written by Jens Axboe <jens.axboe@oracle.com>,
+now Jens Axboe <jaxboe@fusionio.com>.
.br
This man page was written by Aaron Carroll <aaronc@cse.unsw.edu.au> based
on documentation by Jens Axboe.
projects / fio.git / blobdiff