--help Print this page
--cmdhelp=cmd Print command help, "all" for all of them
--showcmd Turn a job file into command line options
+ --readonly Turn on safety read-only checks
+ --eta=when When ETA estimate should be printed
+ May be "always", "never" or "auto"
+
Any parameters following the options will be assumed to be job files,
unless they match a job file parameter. You can add as many as you want,
each job file will be regarded as a separate group and fio will stonewall
its execution.
+The --readonly switch is an extra safety guard to prevent accidentically
+turning on a write setting when that is not desired. Fio will only write
+if rw=write/randwrite/rw/randrw is given, but this extra safety net can
+be used as an extra precaution. It will also enable a write check in the
+io engine core to prevent an accidental write due to a fio bug.
+
Job file
--------
size=x Set file size to x bytes (x string can include k/m/g)
ioengine=x 'x' may be: aio/libaio/linuxaio for Linux aio,
posixaio for POSIX aio, sync for regular read/write io,
- mmap for mmap'ed io, syslet-rw for syslet driven
- read/write, splice for using splice/vmsplice,
- sgio for direct SG_IO io, net for network io, or cpuio
- for a cycler burner load. sgio only works on Linux on
- SCSI (or SCSI-like devices, such as usb-storage or
- sata/libata driven) devices. Fio also has a null io
- engine, which is mainly used for testing fio itself.
+ psync for regular pread/pwrite io, mmap for mmap'ed io,
+ syslet-rw for syslet driven read/write, splice for using
+ splice/vmsplice, sgio for direct SG_IO io, net for
+ network io, or cpuio for a cycler burner load. sgio only
+ works on Linux on SCSI (or SCSI-like devices, such as
+ usb-storage or sata/libata driven) devices. Fio also has
+ a null io engine, which is mainly used for testing fio
+ itself.
iodepth=x For async io, allow 'x' ios in flight
overwrite=x If 'x', layout a write file first.
nrfiles=x Spread io load over 'x' number of files per job,