- https://www.cyberciti.biz/tips/linux-raid-increase-resync-rebuild-speed.html
# echo 50000 > /proc/sys/dev/raid/speed_limit_min
# echo 500000 > /proc/sys/dev/raid/speed_limit_max
# echo 50000 > /proc/sys/dev/raid/speed_limit_min
# echo 500000 > /proc/sys/dev/raid/speed_limit_max