Hey Jocelyn, very hard to tell... i run some test traffic on both [ mq-deadline and none ] and they're both giving 0% IO wait, haven't tested on NVME.

Dnia 17 września 2019 16:16 jocelyn fournier <jocelyn.fournier@gmail.com> napisał(a):

Hi!

Le 17 sept. 2019 à 16:07, pslawek83 <pslawek83@o2.pl> a écrit :

Hi Everyone, just some quick follow up on this topic about MyRocks i started. It seems that there are some issues with debian9 and cfq scheduler when using rocks. Tested this on VM, not sure how virtualization is affecting this. Rocks is easily able to saturate 3 cpu cores with I/O wait and I/O throughput is very low in this config, even on fast SSD.

This gets much better after switching to noop/deadline and best is to switch to Debian10 with mq-deadline. Then I/O wait drops to 0% and performance improves a lot.

Just curious, is mq-deadline faster than none, even on fast SSD / NVME?

Thanks!
Jocelyn