IO engine How do we issue io? We could be memory mapping the
file, we could be using regular read/write, we
- could be using splice, async io, syslet, or even
- SG (SCSI generic sg).
+ could be using splice, async io, or even SG
+ (SCSI generic sg).
IO depth If the io engine is async, how large a queuing
depth do we want to maintain?
filename=str Fio normally makes up a filename based on the job name,
thread number, and file number. If you want to share
files between threads in a job or several jobs, specify
- a filename for each of them to override the default. If
- the ioengine used is 'net', the filename is the host, port,
- and protocol to use in the format of =host,port,protocol.
- See ioengine=net for more. If the ioengine is file based, you
- can specify a number of files by separating the names with a
- ':' colon. So if you wanted a job to open /dev/sda and /dev/sdb
- as the two working files, you would use
- filename=/dev/sda:/dev/sdb. On Windows, disk devices are
- accessed as \\.\PhysicalDrive0 for the first device,
- \\.\PhysicalDrive1 for the second etc. Note: Windows and
- FreeBSD prevent write access to areas of the disk containing
- in-use data (e.g. filesystems).
+ a filename for each of them to override the default.
+ If the ioengine is file based, you can specify a number of
+ files by separating the names with a ':' colon. So if you
+ wanted a job to open /dev/sda and /dev/sdb as the two working
+ files, you would use filename=/dev/sda:/dev/sdb. On Windows,
+ disk devices are accessed as \\.\PhysicalDrive0 for the first
+ device, \\.\PhysicalDrive1 for the second etc. Note: Windows
+ and FreeBSD prevent write access to areas of the disk
+ containing in-use data (e.g. filesystems).
If the wanted filename does need to include a colon, then
escape that with a '\' character. For instance, if the filename
is "/dev/dsk/foo@3,0:c", then you would use
default of $jobname.$jobnum.$filenum will be used if
no other format specifier is given.
+unique_filename=bool To avoid collisions between networked clients, fio
+ defaults to prefixing any generated filenames (with a directory
+ specified) with the source of the client connecting. To disable
+ this behavior, set this option to 0.
+
opendir=str Tell fio to recursively add any file it can find in this
directory and down the file system tree.
the next. Multiple files can still be
open depending on 'openfiles'.
- The string can have a number appended, indicating how
- often to switch to a new file. So if option random:4 is
- given, fio will switch to a new random file after 4 ios
- have been issued.
+ zipf Use a zipfian distribution to decide what file
+ to access.
+
+ pareto Use a pareto distribution to decide what file
+ to access.
+
+ gauss Use a gaussian (normal) distribution to decide
+ what file to access.
+
+ For random, roundrobin, and sequential, a postfix can be
+ appended to tell fio how many I/Os to issue before switching
+ to a new file. For example, specifying
+ 'file_service_type=random:8' would cause fio to issue 8 I/Os
+ before selecting a new file at random. For the non-uniform
+ distributions, a floating point postfix can be given to
+ influence how the distribution is skewed. See
+ 'random_distribution' for a description of how that would work.
ioengine=str Defines how the job issues io to the file. The following
types are defined:
vsync Basic readv(2) or writev(2) IO.
- psyncv Basic preadv(2) or pwritev(2) IO.
+ pvsync Basic preadv(2) or pwritev(2) IO.
+
+ pvsync2 Basic preadv2(2) or pwritev2(2) IO.
libaio Linux native asynchronous io. Note that Linux
may only support queued behaviour with
vmsplice(2) to transfer data from user
space to the kernel.
- syslet-rw Use the syslet system calls to make
- regular read/write async.
-
sg SCSI generic sg v3 io. May either be
synchronous using the SG_IO ioctl, or if
the target is an sg character device
cpuio Doesn't transfer any data, but burns CPU
cycles according to the cpuload= and
- cpucycle= options. Setting cpuload=85
+ cpuchunks= options. Setting cpuload=85
will cause that job to do nothing but burn
85% of the CPU. In case of SMP machines,
use numjobs=<no_of_cpu> to get desired CPU
default is to wait for each job to finish.
bwavgtime=int Average the calculated bandwidth over the given time. Value
- is specified in milliseconds.
+ is specified in milliseconds. If the job also does bandwidth
+ logging through 'write_bw_log', then the minimum of this option
+ and 'log_avg_msec' will be used. Default: 500ms.
iopsavgtime=int Average the calculated IOPS over the given time. Value
- is specified in milliseconds.
+ is specified in milliseconds. If the job also does IOPS logging
+ through 'write_iops_log', then the minimum of this option and
+ 'log_avg_msec' will be used. Default: 500ms.
create_serialize=bool If true, serialize the file creating for the jobs.
This may be handy to avoid interleaving of data
projects / fio.git / blobdiff