[Ubuntu-ma] Monitoring linux

[Nordin]

  Salam alikoum Hassan,

As you're an experienced administrator, I hope you can give me some tips 
and advises.
I'm planning to administer some linux servers hosted at clients. I don't 
know yet what services will be running on their Linux, but the important 
thing is for me to administer these servers. One way to login to their 
systems is using ssh. But that's when I really need to access their 
system. But what's important is to receive system status info from time 
to time. What is the best way to get informed of server status hosting 
at clients?

Thank you for your time.