rw=x 'x' may be: read, randread, write, randwrite,
rw (read-write mix), randrw (read-write random mix)
rwmixcycle=x Base cycle for switching between read and write
rw=x 'x' may be: read, randread, write, randwrite,
rw (read-write mix), randrw (read-write random mix)
rwmixcycle=x Base cycle for switching between read and write