Jens, thanks for the reply. I also tried the following as the HOWTO suggested, and getting similar results [devices] filename=/dev/mapper/raid0:/dev/mapper/raid1 This may be silly part on me misreading the manual, what's correct way of specifying multiple devices? thanks Alex On Wed, Jul 2, 2014 at 3:50 PM, Jens Axboe <axboe@xxxxxxxxx> wrote: > On 07/02/2014 01:42 PM, Yuyang (Alex) Wang wrote: >> hi all, >> >> I am using FIO (2.1.7) to profile block level performance of multiple >> RAID devices. (see config file below). The test is done on a capable >> 16-core server. With a sigle raid device, I am getting roughly >> 1.4GB/s, with two devices in place, I am still getting around 1.4GB/s, >> which is weird. Another in-house developed benchmark tool, running >> SINGLE-thread suggested we can almost double. I could get double the >> performance through FIO by configuring two jobs, with each job >> handling one device only. However, it still puzzles me as to why a >> single process FIO can't drive the performance of two devices. Did I >> do anything wrong as to the configure file? >> >> Thanks >> >> Alex. >> >> >> [globals] >> >> rw=write >> ioengine=libaio >> iodepth=16 >> direct=1 >> blocksize=1m >> runtime=30 >> >> [devices] >> filename=/dev/mapper/raid-0 >> filename=/dev/mapper/raid-1 > > You are overwriting filename here, hence running with just one device. > > -- > 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
