The ability to monitor and control processes and services in your system is essential because of the profound influence they have on the operation and performance of your whole system. The more you know about what each process or service is up to, the easier it will be to pinpoint and solve problems when they creep in.
The most common tasks associated with managing services running on the hardware node or inside a virtual machine or container are starting, stopping, enabling, and disabling a service. For example, you might need to start a service in order to use certain server-based applications, or you might need to stop or pause a service in order to perform testing or to troubleshoot a problem.
For xinetd-dependent services, you do not start and stop but enable and disable services. The services enabled in this way are started and stopped on the basis of the corresponding state of the xinetd daemon. Disabled services are not started whatever the xinetd state.
In OpenVZ, you can manage services on the hardware node and inside containers by means of special Linux command-line utilities. You can do it either locally or from any server connected on the network.
As for processes, such OpenVZ utilities as vzps, vztop, vzpid enable you to see what a process is doing and to control it. Sometimes, your system may experience problems such as slowness or instability, and using these utilities can help you improve your ability to track down the causes. It goes without saying that in OpenVZ you can perform all those operations on processes you can do in a normal system, for example, kill a process by sending a terminate signal to it.
