usb-storage or sata/libata driven) devices.
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,
+ if possible.
prio=x Run io at prio X, 0-7 is the kernel allowed range
prioclass=x Run io at prio class X
bs=x Use 'x' for thread blocksize. May include k/m postfix.
bwavgtime=x Average bandwidth stats over an x msec window.
create_serialize=x If 'x', serialize file creation.
create_fsync=x If 'x', run fsync() after file creation.
+ unlink If set, unlink files when done.
end_fsync=x If 'x', run fsync() after end-of-job.
loops=x Run the job 'x' number of times.
verify=x If 'x' == md5, use md5 for verifies. If 'x' == crc32,
write_iolog=x Write an iolog to file 'x' in the same format as iolog.
The iolog options are exclusive, if both given the
read iolog will be performed.
+ write_bw_log Write a bandwidth log.
+ write_lat_log Write a latency log.
lockmem=x Lock down x amount of memory on the machine, to
simulate a machine with less memory available. x can
include k/m/g suffix.