[ ... ] > I have setup an array of 7x3tb WD30EZRX drives, though its > meant for 8x, so it runs in singledegraded mode. An (euphemism) amazing concept, with (euphemism) surprising effects: > the issue is that i get very poor performance, generally > roughly 25MB/s writes only. [ ... ] > Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s [ ... ] > sdb 1370.00 732.00 109.00 30.00 11824.00 5864.00 [ ... ] > sdf 1392.00 839.00 88.00 33.00 11840.00 6976.00 [ ... ] > sdd 1422.00 863.00 64.00 29.00 13448.00 6384.00 [ ... ] > sdg 1388.00 446.00 92.00 18.00 11840.00 3248.00 [ ... ] > sdc 1395.00 857.00 85.00 40.00 11840.00 6944.00 [ ... ] > sda 1370.00 985.00 111.00 41.00 11888.00 7744.00 [ ... ] > sde 1417.00 669.00 70.00 21.00 13528.00 5040.00 [ ... ] > sdh 0.00 0.00 0.00 0.00 0.00 0.00 [ ... ] > md0 0.00 0.00 0.00 86.00 0.00 17656.00 [ ... ] > dm-0 0.00 0.00 0.00 0.00 0.00 0.00 [ ... ] It is (euphemism) mysterious that 'rsec/s' is nearly twice as high as 'wsec/s', and (euphemism) obscure that the RAID set is also 'sync'ing: > Number Major Minor RaidDevice State > 0 8 0 0 active sync /dev/sda > 1 8 16 1 active sync /dev/sdb > 2 8 32 2 active sync /dev/sdc > 3 8 48 3 active sync /dev/sdd > 4 8 64 4 active sync /dev/sde > 5 8 80 5 active sync /dev/sdf > 8 8 96 6 active sync /dev/sdg > 7 0 0 7 removed > [ ... ] so i must assume the issue is in the raid layer. Or perhaps in the greyware layer :-). -- 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
