> 1. With request based multipath, we have 2 elevators in the > path to the device. Doesn't 2 idling I/O schedulers affect > performance? Is it better to use the noop elevator for the > dm device? [ ... ] Usually "metadrivers" (DM, MD, 'loop', ...) in Linux use only one elevator (and it should be that of the _physical device_). But if you are concerned by that kind of stuff, consider also the impact of the (short-sightedly idiotic, and IIRC it cannot be disabled) plugging/unplugging logic. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
