On Sun, Oct 4, 2015 at 8:03 AM, Lionel Bouton <lionel-subscription@xxxxxxxxxxx> wrote: > > This focus on single reader RAID1 performance surprises me. > > 1/ AFAIK the kernel md RAID1 code behaves the same (last time I checked > you need 2 processes to read from 2 devices at once) and I've never seen > anyone arguing that the current md code is unstable. Perhaps, but with btrfs it wouldn't be hard to get 1000 processes reading from a raid1 in btrfs and have every single request directed to the same disk with the other disk remaining completely idle. I believe the algorithm is just whether the pid is even or odd, and doesn't take into account disk activity at all, let alone disk performance or anything more sophisticated than that. I'm sure md does a better job than that. -- Rich -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
