* Holger Kiehl (Holger.Kiehl@xxxxxx) wrote: > There is however one difference, here I had set > /sys/block/sd?/queue/nr_requests to 4096. Well from that it looks like none of the queues get about 255 (hmm that's a round number....) > avg-cpu: %user %nice %sys %iowait %idle > 0.10 0.00 21.85 58.55 19.50 Fair amount of system time. > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s rkB/s wkB/s > avgrq-sz avgqu-sz await svctm %util > sdf 11314.90 0.00 365.10 0.00 93440.00 0.00 46720.00 0.00 > 255.93 1.92 5.26 2.74 99.98 > sdg 7973.20 0.00 257.20 0.00 65843.20 0.00 32921.60 0.00 > 256.00 1.94 7.53 3.89 100.01 There seems to be quite a spread of read performance accross the drives (pretty consistent accross the run); what makes sdg so much slower than sdf (which seems to be the slowest and fastest drives respectively). I guess if everyone was running at sdf's speed you would be pretty happy. If you physically swap f and g does the performance follow the drive or the letter? Dave -- -----Open up your eyes, open up your mind, open up your code ------- / Dr. David Alan Gilbert | Running GNU/Linux on Alpha,68K| Happy \ \ gro.gilbert @ treblig.org | MIPS,x86,ARM,SPARC,PPC & HPPA | In Hex / \ _________________________|_____ http://www.treblig.org |_______/ - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html