Thanks for your reply, indeed my interest to get the max iops but on a filesystem not a raw device, I understand the penalty but that would be more realstic for production systems. I will try these changes and keep you updated . All the best H. N. Harake ________________________________________ From: Jens Axboe [jaxboe@xxxxxxxxxxxx] Sent: Tuesday, March 15, 2011 9:28 PM To: N. Harake Cc: fio@xxxxxxxxxxxxxxx Subject: Re: memory caching On 2011-03-15 13:36, N. Harake wrote: > > I noticed when I am using --sync=1, IOPS go down to 15K and throughput to > 53MB (That¹s horrible for the HW I am using), removing --sync I got 150K > IOPS and almost 800MB, which make more sense. What does --sync does, and > hope what I am doing should be enough to avoid any kind of memory caching.. > > Regards > H. N. Harake > > fio --name=job --directory=/lvm --size=1G --iodepth=1 --sync=1 > --filesize=1G --direct=1 --numjobs=64 --bs=4096 --rw=randwrite > --group_reporting If your goal is to maximize iops for testing, use the raw block device. Use direct=1, and ioengine=libaio. Set depth large, ala: --iodepth=128 --iodepth_batch_complete=8 --iodepth_batch_submit=8 -- 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
