number_of_disks=5 chunksize_in_kib=512 chunksize_in_b=$[chunksize_in_kib*1024] array_data_size_in_kib=$[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 $dev4" # default 2048 sectors data_offset_in_kib=$[2048/2] # make a raid5 from a file dd if=/dev/urandom of=/tmp/RandFile bs=1024 count=$array_data_size_in_kib # perform test for every layout layouts="ls rs la ra parity-first ddf-zero-restart ddf-N-restart ddf-N-continue \ left-asymmetric-6 right-asymmetric-6 left-symmetric-6 \ right-symmetric-6 parity-first-6" for layout in $layouts do mdadm -CR $md0 -l6 --layout=$layout -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 cmp -s -n $array_data_size_in_b $md0 /tmp/RandFile || { echo sanity cmp failed ; exit 2; } # wipe out 5 chunks on each device dd if=/dev/urandom of=$dev0 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*0] dd if=/dev/urandom of=$dev1 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*5] dd if=/dev/urandom of=$dev2 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*10] dd if=/dev/urandom of=$dev3 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*15] dd if=/dev/urandom of=$dev4 bs=1024 count=$[5*chunksize_in_kib] seek=$[data_offset_in_kib+chunksize_in_kib*20] blockdev --flushbufs $devs; sync echo 3 > /proc/sys/vm/drop_caches $dir/raid6check $md0 0 0 2>&1 | grep -qs "Error" || { echo should detect errors; exit 2; } $dir/raid6check $md0 0 0 autorepair > /dev/null || { echo repair failed; exit 2; } blockdev --flushbufs $md0 $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 cmp failed ; exit 2; } mdadm -S $md0 done