View Running Services in Linux: A Quick Guide to Monitoring Services

Are you a Linux user who wants to keep track of the services running on your system? Monitoring services is an essential task for system administrators and users who want to ensure the smooth operation of their Linux machines. In this comprehensive guide, we will explore various methods to view running services in Linux, providing you with the knowledge and tools to effectively monitor and manage your system.

Introduction

In the world of Linux, services are the background processes that run on your system, providing various functionalities and features. These services can range from essential system processes to user-installed applications. Monitoring these services is crucial for troubleshooting, performance optimization, and security purposes.

There are several ways to view running services in Linux, each with its own set of commands and tools. In this guide, we will cover the most commonly used methods, including systemctl, service, initctl, chkconfig, ps, top, htop, netstat, lsof, ss, pstree, systemd-cgls, systemd-analyze, and more.

1. Using systemctl

The systemctl command is a powerful tool for managing and monitoring services in Linux. It is the standard command-line interface to control the systemd system and service manager. To view running services using systemctl, you can use the following commands:

systemctl list-units: This command displays a list of all active units (services, sockets, devices, etc.) on your system.

systemctl list-unit-files: This command lists all available unit files, including both enabled and disabled units.

systemctl status [service]: This command provides detailed information about a specific service, including its status, process ID, memory usage, and more.

systemctl show [service]: This command displays detailed information about a service, including its configuration, dependencies, and more.

systemctl is-active [service]: This command checks if a service is currently active or not.

systemctl is-enabled [service]: This command checks if a service is enabled to start at boot or not.

systemctl is-failed [service]: This command checks if a service has failed or not.

2. Using service

The service command is a legacy command used to control system services in Linux. While systemctl is the recommended method for managing services, the service command is still widely used. To view running services using service, you can use the following commands:

service –status-all: This command displays the status of all services on your system.

service –status-all | grep running: This command filters the output of the previous command to only show running services.

3. Using initctl

The initctl command is used to control the Upstart init system, which is used by some Linux distributions. To view running services using initctl, you can use the following commands:

initctl list: This command lists all running services managed by Upstart.

initctl status [service]: This command provides detailed information about a specific service managed by Upstart.

4. Using chkconfig

The chkconfig command is used to manage services controlled by the SysV init system. To view running services using chkconfig, you can use the following command:

chkconfig –list: This command lists all services and their current runlevel status.

5. Using ps

The ps command is a versatile command-line tool for displaying information about running processes. To view running services using ps, you can use the following commands:

ps -ef: This command displays a detailed list of all processes running on your system.

ps aux: This command provides a more concise output of all processes, including additional information such as CPU and memory usage.

6. Using top

The top command is a real-time process monitoring tool that provides a dynamic view of the processes running on your system. To view running services using top, you can use the following command:

top -c: This command displays a continuously updated list of processes, sorted by CPU usage.

7. Using htop

Htop is an interactive process viewer and system monitor that provides a more user-friendly and feature-rich alternative to the top command. To view running services using htop, you can use the following command:

htop -u: This command launches htop and filters the processes to only show user-owned processes.

8. Using netstat

The netstat command is a powerful network monitoring tool that provides information about network connections, routing tables, and network interface statistics. To view running services using netstat, you can use the following command:

netstat -tuln: This command displays a list of all listening TCP and UDP ports on your system.

9. Using lsof

The lsof command (short for “list open files”) is a versatile tool for displaying information about files opened by processes. To view running services using lsof, you can use the following command:

lsof -i: This command lists all network connections opened by processes on your system.

10. Using ss

The ss command (short for “socket statistics”) is a modern replacement for netstat that provides detailed information about network sockets. To view running services using ss, you can use the following command:

ss -tuln: This command displays a list of all listening TCP and UDP sockets on your system.

11. Using pstree

The pstree command displays a tree-like representation of processes on your system, showing their parent-child relationships. To view running services using pstree, you can use the following command:

pstree -p: This command displays a process tree with process IDs.

12. Using systemd-cgls

The systemd-cgls command is used to display the hierarchy of control groups managed by systemd. To view running services using systemd-cgls, you can use the following command:

systemd-cgls -a: This command displays a tree-like representation of control groups, including services.

13. Using systemd-analyze

The systemd-analyze command provides diagnostic and performance information about the systemd system and service manager. To view running services using systemd-analyze, you can use the following command:

systemd-analyze blame: This command displays a list of services ordered by the time they took to start during the boot process.

Conclusion

Monitoring running services in Linux is essential for maintaining system stability, performance, and security. In this guide, we have explored various methods to view running services, including systemctl, service, initctl, chkconfig, ps, top, htop, netstat, lsof, ss, pstree, systemd-cgls, and systemd-analyze. By utilizing these tools and commands, you can effectively monitor and manage the services running on your Linux system.

FAQs

1. How can I check if a specific service is running in Linux?

To check if a specific service is running in Linux, you can use the systemctl status [service] command. This command will provide detailed information about the service, including its status, process ID, and more.

2. Can I view running services on remote Linux machines?

Yes, you can view running services on remote Linux machines by using SSH (Secure Shell) to connect to the remote machine and then executing the appropriate commands, such as systemctl or service, to view the running services.

3. How often should I monitor running services in Linux?

It is recommended to monitor running services in Linux regularly, especially if you are a system administrator or responsible for the maintenance of a Linux server. Regular monitoring can help identify any issues or abnormalities with the services and ensure the smooth operation of the system.