Bug#361674: please do not use mdrun at all

[dean gaudet <dean@arctic.org>]

mdrun does not respect the device minor numbers at all... this can totally 
mess up the ordering of md devices and screw with static mounts (note that 
while mounting by label/uuid is preferable it isn't always available -- 
for example XFS external log partitions cannot be specified by label or 
uuid).

see bug#354705 -- mdrun is set to be deprecated.

it would eliminate a lot of linux-raid bug reports if initramfs-tools 
would set up only the root raid, using something like i've suggested (and 
tested) for yaird in bug#351183:

	mdadm -Ac partitions /dev/md$N --uuid $UUID

there is further discussion of initramfs in modern mdadm packages (i.e. 
2.4.1) in README.initramfs... for example you may wish to add 
"--auto=part" to that command as well.

thanks
-dean