Linux is probably less popular than Windows and Mac in terms of desktop computer. But, the different story goes to server. Linux is by far the most-adopted operating system for server computers. Big websites such as Wikipedia and Google also use Linux to power their servers.

There is a man behind a big site whose his job is to ensure the Linux machine runs how it is supposed to be. He is system administrator or also called sysadmin.

Sysadmin’s job is not easy. He is responsible to entire system. When something bad is happen, he will be blamed so easily and no one care about him. But, don’t too worry. As long as you have a good skill and prepare your mentality as well, everything will be okay.

If you aspire to become a sysadmin, you have to at least know the following tools. The tools below are great for monitoring the performance of Linux machine you are responsible to.

Linux server monitoring tools

1. Top

Top is the most common tool used by a sysadmin to get the overview of all the current processes on Linux. Top is very basic tool which pre-installed in nearly all Linux distros. No complex parameters are needed to use the tool. Once typed top in terminal you can see things like the current time, uptime, the number of running tasks, percentage of CPU and memory usage and lots more. You can also kill a certain task by entering the “k” button of your keyboard followed by the PID (ID of the processes)

#top

2. Uptime

You will need this tool to figure out how long your Linux machine has been running. Just hit the uptime command in the terminal and Linux system will show you how long your machine has been running, current time, the number of logged user and load average. You can also find out since when your machine was turned on using “s” parameter.

#uptime --help

3. Vmstat

Vmstat is a tool that monitors and displays a summary about the memory in the machine. You will need this tool to check some things related to the memory of your machine. Not all Linux distros have included this tool as their default tool so you might have to install it by yourself.

#vmstat --help

4. Htop

Htop is another tool to see the running processes of your system. This is the enhanced version of reguler top. One key feature that make htop different to top is percentage bar that makes it easier to check the availability of your memory. Htop also offers a colorful interface. You can also see the tree of all the processes by pressing the F5 button.

#htop

5. Atop

Again. Atop is also a tool to see the running processes like top and htop. What makes it different?.

Atop is tend to ideal for long-term analysis because it has daily logging of the processes which you can read using “-r” parameter. The logs usually located at /var/log/atop. Atop also shows resource consumption by all processes and highlight resources that have reached a critical load.

#atop --help

6. Iotop

The use of iotop is to display I/O usage information. You will see a top-alike interface. This tool requires a root privilege to run. Once executed, it will display columns on read and write and each row represents a process. It also displays the percentage of time the process spent while swapping in and while waiting on I/O.

#iotop

7. Iostat

Iostat is a part of sysstat utility. You can use this tool to monitor system input/output. The reports themselves can be used to change system configurations to better balance input/output load between hard drives in your machine.

#iostat

8. Free

If your system is running slowly, it might caused by the low remaining memory. Free is a handy tool that you can use to monitor the memory usage of your system. It shows the total memory, used memory and free memory on your system. By default, free will display the number of memory in byte. You can change the unit to kilobyte, megabyte or gigabyte by adding -k, -m or -g parameters.

#free --help

9. Nmon

Nmon is another great tool for monitoring your system performance. This is a versatile tool that you can use to find out the usage of CPU, memory disk to network. Your Linux distro might not offering this tool by default so you have to install it by yourself.

#nmon

PS

If you have been a Linux system administrator and are looking for a comprehensive system administration tool, Loggly is a tool you can give a try. It is a paid tool, but there is a trial version to allow you to figure out if it is really the tool you need. You can use Loggly to check the error logs of your Linux system if something is not running as usual. This tool offers cloud-based log aggregation with an agentless approach for collecting logs.