Command line for bind not working

Hi,

I notice occasionally (once every few months), bind DNS server stops working. I can press the "Start" button to start bind via virtualmin.

Now i want to be more proactive about this issue, i want to make a cron job to monitor, and start bind if it is not working.

However, i try the commands for bind, none of them seems to work

service bind9 status returns nothing

service bind9 start return nothing

So, i'd like to ask what should be the correct syntax for bind?

I'm using ubuntu 16.04, 64 bit.

Thanks!