With the quickest and easiest fix (the first suggestion from Jens Axboe), I was able to get another 20%+ in IOPS. Thank you. (Pardon the previous ugly wrap on the data. I'm not sure how to stop that with my e-mail vendor) Driving more IOPS on the same system looks like this for me: CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle all 2.85 0.00 31.37 12.05 0.00 14.84 0.00 0.00 38.90 0 2.44 0.00 0.00 0.00 0.00 4.39 0.00 0.00 93.17 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 2 1.51 0.00 23.12 70.85 0.00 4.52 0.00 0.00 0.00 3 5.05 0.00 51.01 19.70 0.00 24.24 0.00 0.00 0.00 4 5.47 0.00 62.19 1.00 0.00 31.34 0.00 0.00 0.00 5 4.00 0.00 50.00 22.50 0.00 23.50 0.00 0.00 0.00 6 0.00 0.00 0.00 0.00 0.00 0.47 0.00 0.00 99.53 7 0.00 0.00 0.22 0.00 0.00 0.00 0.00 0.00 99.78 8 4.48 0.00 53.23 16.92 0.00 25.37 0.00 0.00 0.00 9 4.48 0.00 50.25 19.40 0.00 25.87 0.00 0.00 0.00 10 5.53 0.00 63.82 0.50 0.00 30.15 0.00 0.00 0.00 11 3.50 0.00 52.00 20.50 0.00 24.00 0.00 0.00 0.00 12 0.50 0.00 1.00 1.49 0.00 0.00 0.00 0.00 97.01 13 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 14 3.50 0.00 43.50 35.50 0.00 17.50 0.00 0.00 0.00 15 4.02 0.00 51.26 20.60 0.00 24.12 0.00 0.00 0.00 16 6.03 0.00 57.29 8.54 0.00 28.14 0.00 0.00 0.00 17 4.50 0.00 49.00 25.00 0.00 21.50 0.00 0.00 0.00 18 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 19 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 100.00 20 4.98 0.00 57.21 11.44 0.00 26.37 0.00 0.00 0.00 21 4.50 0.00 54.00 16.00 0.00 25.50 0.00 0.00 0.00 22 5.50 0.00 58.00 7.00 0.00 29.50 0.00 0.00 0.00 23 4.00 0.00 49.50 22.50 0.00 24.00 0.00 0.00 0.00 I'm happy to have the performance improvement, but I would like to know how I could do much better. The storage hardware is all capable of about twice the IOPS I'm getting now. I see that "sys" is eating most of the CPU time at this point. What do I need to fix? Is fio too heavy in implementation? ... or is this a scsi midlayer bottleneck? I would be happy to get advice on what I should do to better illuminate the bottleneck. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
