b333z/zfs — pull request #1 by GregorKopka (2013-05-24 19:30:59+00:00)
Title: Issue 1461 - rough idea how to select mirror vdev member by estimated queue service time

Warning upfront: I doubt the pull request will compile, apart from 'Hello World' i never coded C - so please **digest this as pseudocode** and indulge me for serving this **untested**

Idea is to track average request duration (256 recent requests) for each vdev and select children for ready by queue lenght * average request duration.