On 4/13/11, Rudi Ahlers <Rudi at softdux.com> wrote: >> to expand the array :) > > I haven't had problems doing it this way yet. I finally figured out my mistake creating the raid devices and got a working RAID 0 on two RAID 1 arrays. But I wasn't able to add another RAID 1 component to the array with the error mdadm: add new device failed for /dev/md/mdr1_3 as 2: Invalid argument Googling up this indicates that it's the expected result trying to add a new device to a RAID 0 array. Could you or anybody else please share what's the trick to achieving this?