Comparing RAID-5 to RAID-0

We also want to know how performance degrades if we use RAID-5 instead of RAID-0.

3ware BIOS allows 64k RAID-5 stripe size only.
The formatted capacity of 7+1 disk configuration is 1636 MiB.
XFS was formatted with -d su=64k,sw=7 option.

bonnie -u nobody -d . -s 1024 -n 16 -r 64

bonnie -u nobody -d . -s 1024 -n 16

time sh -c "dd if=/dev/zero bs=64k count=16384 of=jonagy ; sync"
time dd of=/dev/null bs=64k count=16384 if=jonagy

time sh -c "dd if=/dev/zero bs=1024k count=65536 of=jonagy2 ; sync"
time dd of=/dev/null bs=1024k count=65536 if=jonagy2

cstream -B 1m -b 1m -n 1024m -i - -o cgigasz -v 2
cstream -B 1m -b 1m -n 1024m -o - -i cgigasz -v 2

cstream -B 1m -b 1m -n 65536m -i - -o cgigasz2 -v 2
cstream -B 1m -b 1m -n 65536m -o - -i cgigasz2 -v 2

Conclusions

Write throughput degraded tragically: with 80 % or so. Bonnie shows significant slowing of read operations too, the other two tests do not.