Hi, On 25 May 2017 at 18:15, Ratn, Prasun <Prasun.Ratn@xxxxxxx> wrote: > > I am trying to run fio on a raw NVMe drive using 2 jobs with QD=4. > > I am not sure how to specify the offsets for each job to write to. I tried using offset_increment but that doesn't seem to work. > > The first run with 1 job runs smoothly. > > $ sudo fio --rw=randwrite --bs=4k --name=/dev/nvme0n1 --runtime=10 --direct=1 --ioengine=libaio --iodepth=4 [...] > > When I try specifying numjobs=2 with offset_increment, I get an error and only 1 process is launched. > > > $ sudo fio --rw=randwrite --bs=4k --name=/dev/nvme0n1 --runtime=10 --direct=1 --ioengine=libaio --iodepth=4 --numjobs=2 --offset_increment=81920m > /dev/nvme0n1: (g=0): rw=randwrite, bs=4k-4k/4k-4k/4k-4k, ioengine=libaio, iodepth=4 > ... > fio-2.2.8 > starting 2 processes > /dev/nvme0n1: you need to specify size= > fio: pid=0, err=22/file:filesetup.c:802, func=total_file_size, error=invalid argument > ^cbs: 1 (f=1): [w(1),x(1)] [54.5% done] [0kb/510.2mb/0kb /s] [0/131k/0 iops] [eta 00m:05s] > fio: terminating on signal 2 > > What's the best way to have multiple jobs run on a single raw drive. Because you don't want fio to "invent" the name of the file you are are doing I/O to you're better off using a filename job parameter and then the name of your job can be whatever you like e.g. fio --rw=randwrite --bs=4k --filename=/dev/nvme0n1 --runtime=10 --direct=1 --ioengine=libaio --iodepth=4 --numjobs=2 --offset_increment=81920m --name=randomwrites (all the job parameters were global) or fio --rw=randwrite --bs=4k --name=randomwrites --filename=/dev/nvme0n1 --runtime=10 --direct=1 --ioengine=libaio --iodepth=4 --numjobs=2 --offset_increment=81920m (two parameters were global but achieving an identical effect) See http://fio.readthedocs.io/en/latest/fio_doc.html#cmdoption-arg-filename for details and http://fio.readthedocs.io/en/latest/fio_doc.html#cmdoption-arg-size for how the size semantics change when filename is used. Tip: if you don't want the regions the jobs do I/O against to overlap (which I'm guessing is why you already have offset_increment) you'll need to set the size parameter too. -- Sitsofe | http://sucs.org/~sits/ -- 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
