> If you only have 2 drives there's not much you can do to avoid concurrent > access. The killer is head seek time - if you have your only 2 drives > tied together in any kind of raid and the head needs to be in 2 places at > once it doesn't matter much how you laid out the partitions. Reads can be > sort-of independent on raid1 but writes make both seek to the same place. > That's not what I was referring to. I meant, for example, that if you have on the same disks a RAID-0 containing data that is very frequently used and a RAID-1 containing data that is rarelly accessed, then you still beneffit from the qualities of both RAID types despite them being on the same physical disks.