I seem to have hit a significant hard stop in MD RAID1/10 performance which seems to be linked to a single CPU thread. I am using extremely high speed (IOPS) internal block devices – 8 in total. They are capable of achieving > 1million iops. However if I use RAID1 / 10 then MD seems to use a single thread which will reach 100% CPU utilisation (single core) at around 200K IOPS. Limiting the entire performance to around 200K. If I use say 4 x RAID1 / 10’s and a RAID0 on top – I see not much greater results. (although the theory seems to say I should and there are now 4 CPU threads running, it still seems to hit 4 x 100% at maybe 350K). Is there any way to increase the number of threads per RAID set? Or any other suggestions on configurations? (I have tried every permutation of R0+R1/10’s) Thank you for any advice. Mark -- 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
