Synology Raid Rebuild – Speed up the rebuild process

Telnet to the Synology NAS, login in a root.   (You may need to enable Telnet Server first)

Raid Stats Command
cat /proc/mdstat

Default Raid Values
cat /proc/sys/dev/raid/speed_limit_max
cat /proc/sys/dev/raid/speed_limit_min

Improve Rebuild Speed  –  increase the speed_limit_min value.
echo 40000 > /proc/sys/dev/raid/speed_limit_min

check speed with
cat /proc/mdstat
Max speed on my DS1812+ with DSM5.1  was just under 40000K/sec
So 3TB Disk took approx 20hrs to rebuild