Chapter 4: Operating System Monitoring
Chapter contents
This section describes how to monitor the various operating system functions. This includes:
●Gathering system information
●Monitoring system processes
●Additional resources
Gathering system information
Before configuring your operating system, you gather essential system information using simple Linux commands and programs. For example, you should know
●how to find the amount of free memory,
●the amount of available hard drive space,
●how your hard drive is partitioned, and
●what processes are running.
Monitoring system processes
The ps ax command displays a list of current system processes. To display the process owner along with the processes, use the command ps aux. This list is a static list; in other words, it is a snapshot of what is running when you invoked the command. If you want a constantly updated list of running processes, use top as described below.
The ps output can be long. To prevent it from scrolling off the screen, you can pipe it through less:
ps aux less
You can use the ps command in combination with the grep command to see if a process is running. For example, to determine if Emacs is running, use the following command:
ps ax grep emacs
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