+io_limit=int Normally fio operates within the region set by 'size', which
+ means that the 'size' option sets both the region and size of
+ IO to be performed. Sometimes that is not what you want. With
+ this option, it is possible to define just the amount of IO
+ that fio should do. For instance, if 'size' is set to 20G and
+ 'io_limit' is set to 5G, fio will perform IO within the first
+ 20G but exit when 5G have been done.
+