sys-fs/mdadm-3.1.1 does install two udev rules files: $ epm -ql mdadm|grep udev /etc/udev/rules.d/64-md-raid.rules /lib/udev/rules.d/64-md-raid.rules But as udev merges all rules directories and priorises them the one from /etc is always used. Message from "udevadm test": udev_rules_new: rule file basename '/etc/udev/rules.d/64-md-raid.rules' already added, ignoring '/lib/udev/rules.d/64-md-raid.rules'
looks like the rules are pretty much the same, so i just dropped it in the current ebuild. thanks for the heads up. http://sources.gentoo.org/sys-fs/mdadm/mdadm-3.1.1.ebuild?r1=1.1&r2=1.2