At this point I would like to find out how hard is it to manage a server.
I don't know if Linux commands are enough, or a software programme should be prefered.
In both cases I would like to hear the advice of the experts of this forum.
In the first case (linux commands) please include a complete series of commands that someone who is colocating should type and have a complete view of his server status.
In the second please specify the best soft for management - identifying which processes should be killed, which accounts/scripts are resource intensive, who is spamming and all the rest.