Hi, On Sat, 11 Aug 2018 at 09:44, Shaonan Ma <msn18@xxxxxxxxxxxxxxxxxxxxx> wrote: > > I am using fio to test performance of a large amount of small files. I use rbd of ceph and map the image to a device, mount the device and write a lot of small files. > > I want to know whether fio can test performance of small files well. > > I use the engine libaio, my config is: > > [global] > ioengine=libaio > buffered=0 > rw=randwrite > bs=4k > size=1G > io_size=1G > iodepth=256 > filesize=4k > nrfiles=256000 > [job1] > directory=rbdmap/rbdmap0 You have one process/fio job that will randomly write to the first file, then choose the next file and randomly write to that and so on. As your block size matches your file size I'd imagine each file will see one I/O until 1GBytes worth of I/O has been done in total (regardless of file). Is that what you intended? > I don't know whether my config is correct. Because I increase the filesize from 4k to 256k, and modify size and io_size. The result of bandwidth and iops is as following: > ^^^ I don't see any results - are you sure you included them inline? What did you increase size and io_size to? > I don't know whether the performance is correct, or fio is not suitable for a lot of small files. This is going to be dependent on your system set u so we're unlikely to know if the number look "right". The ceph folks (http://lists.ceph.com/listinfo.cgi/ceph-community-ceph.com ) might know though... -- Sitsofe | http://sucs.org/~sits/
