i am sending 1MB buffer to a raid of 1MB chunk size. i know that each offset is aligned by the chunk size. On 3/27/06, Jens Axboe <axboe@xxxxxxx> wrote: > > don't top-post! > > On Mon, Mar 27 2006, Raz Ben-Jehuda(caro) wrote: > > I know that. > > Currently i did some stupid stuff in the deadline. > > I am thinking of creating some sort of awaiting list in the raid > > layer by hooking into the make_request. > > > > Let me give u an example: > > when issue 15 iops over a single disk i have an average latency of 580 > > ms ( 1MB IO buffers). > > when i 60 iops over raid5 of 4 disks i am getting 750 ms average latency. > > I believe this is due to non balancing hence non fairness. > > i need some sort of strict batching. > > Do u agree ? > > That raid setup will always get you a little higher latency, simply > because you will be waiting for more disks. As an example - submitting > two ios to separate drives will always get higher latency than just one > of the ios, since you want to wait for both to complete. Throughput may > be better, but that doesn't say anything about the average or max > experienced latency. > > -- > Jens Axboe > > -- Raz - 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
