[plug] rsync - how to tell if working?

[Daniel]

Hello All,
sometimes I'm not sure if rsync is working. Original terminal window has
not returned to prompt.
It's still in 'ps aux | grep rsync' which shows processes using around
4.5% memory, but 0 cpu so guess it must be dead.  
Will rsync just stall and still hang onto memory? 
I have checked directory size and that's remaining stable (as expected
for just an update).
I can just restart it, but could I get around this automatically?

thanks,
Daniel.