number_of_disks=7 chunksize_in_kib=512 array_data_size_in_kib=$[chunksize_in_kib*(number_of_disks-2)*number_of_disks] array_data_size_in_b=$[array_data_size_in_kib*1024] devs="$dev0 $dev1 $dev2 $dev3 $dev4 $dev5 $dev6" dd if=/dev/urandom of=/tmp/RandFile bs=1024 count=$array_data_size_in_kib mdadm -CR $md0 -l6 -n$number_of_disks -c $chunksize_in_kib $devs dd if=/tmp/RandFile of=$md0 bs=1024 count=$array_data_size_in_kib blockdev --flushbufs $md0; sync check wait blockdev --flushbufs $devs; sync echo 3 > /proc/sys/vm/drop_caches $dir/raid6check $md0 repair 1 2 3 > /dev/null # D D $dir/raid6check $md0 repair 8 2 5 > /dev/null # D P $dir/raid6check $md0 repair 15 4 6 > /dev/null # D Q $dir/raid6check $md0 repair 22 5 6 > /dev/null # P Q $dir/raid6check $md0 repair 3 4 0 > /dev/null # Q D $dir/raid6check $md0 repair 3 3 1 > /dev/null # P D $dir/raid6check $md0 repair 6 4 5 > /dev/null # D /dev/null # D>D blockdev --flushbufs $devs; sync echo 3 > /proc/sys/vm/drop_caches $dir/raid6check $md0 0 0 2>&1 | grep -qs "Error" && { echo errors detected; exit 2; } cmp -s -n $array_data_size_in_b $md0 /tmp/RandFile || { echo should not mess up correct stripe ; exit 2; } mdadm -S $md0 udevadm settle