On 04/16/2014 08:21 AM, Yuyang Wang wrote: > hi all > > I am using fio (2.1.7) for a simple sequential write test (see command > below). It seems the process will get stuck on "Laying out IO file" for a > long long time ... Of course, smaller size take less time for layout, I > am curious as to, is FIO trying to precreate the file before doing write, > what's going on there? > > ./fio --rw=write --size=128g --bs=8m --filename=/test/$RANDOM > --ioengine=posixaio --iodepth=16 --name=mytest For a pure write, it wont layout the file completely first. I'm guessing you are stuck in fallocate - depending on the file system, that will fill out blocks. You can try and add fallocate=none, that should get rid of it. -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
