On Tue, 2018-07-10 at 12:45 -0600, Jens Axboe wrote: > The difference between the job file and the > workload run can be huge. Consider something really basic: > > [randwrites] > bs=4k > rw=randwrite > > which would be 100% random 4k writes. If I run this on a zoned device, > then that'd turn into 100% sequential writes. That's not correct. The ZBD code in the github pull request serializes writes per zone, not globally. > > What I derived from the fio source code is as follows (please correct me > > if I got anything wrong): > > * The purpose of the zonesize, zonerange and zoneskip job options is to > > limit the I/O range to a single zone with size "zonesize". The I/O > > pattern for zoned block devices is different: I/O happens in multiple > > zones simultaneously. The number of zones to which I/O happens is > > called the number of open zones. > > The only difference is that fio currently only has one zone active. When > it finishes one, it goes to the next. See my above suggestion on adding > the notion of open zones, which would extend this to more than 1. Thanks, I will look into this. Bart.
