Hello, My three HHDs have following speeds: hda - speed 70 MB/sec hdc - speed 27 MB/sec sda - speed 60 MB/sec They create a raid1 /dev/md0 and raid5 /dev/md1 arrays. I wanted to ask if mdadm is trying to pick the fastest HDD during operation? Maybe I can "tell" which HDD is preferred? This came to my mind when I saw this: # mdadm --query --detail /dev/md1 | grep Prefer Preferred Minor : 1 And also in the manual: -W, --write-mostly [...] "can be useful if mirroring over a slow link." many thanks for all your help! -- Janek Kozicki | - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html