How to Monitor Running System Services on Linux Server - Complete Guide

Are you wondering how to check which system services are running on your Linux server? Need to monitor systemd services and receive alerts when critical services stop? This comprehensive guide shows you multiple methods to check running services, monitor service status changes, detect stopped services, and ensure your Linux server's critical services remain available 24/7.

Why Monitoring Running Services Matters

System services are essential components that keep your Linux server functioning. When critical services like web servers, databases, or application services stop running, your entire infrastructure can fail. Regular monitoring of running services helps you detect stopped services quickly, monitor status of critical services, identify unauthorized services, and maintain system stability to prevent costly downtime incidents.

Method 1: List Running Services with systemctl Command

The systemctl command is the standard way to manage and check systemd services on modern Linux systems.

List All Running Services

To see all currently running services:

# List all running services
systemctl list-units --type=service --state=running

This shows:

• Service names
• Service status (active/running)
• Service descriptions
• Load status

List All Services (Including Stopped)

To see all services including stopped ones:

# List all services
systemctl list-units --type=service --all

This provides a complete view of all services and their states.

Check Specific Service Status

To check if a specific service is running:

# Check if nginx is running
systemctl is-active nginx

# Check if mysql is running
systemctl is-active mysql

# Check multiple services
systemctl is-active nginx mysql redis

This returns "active" if running, "inactive" if stopped, or "failed" if the service has failed.

Method 2: Check Service Status with systemctl status

The systemctl status command provides detailed information about services.

Detailed Service Status

# Detailed status of a service
systemctl status servicename

# Status with no pager
systemctl status servicename --no-pager

This shows:

• Current service state
• Process ID (PID)
• Recent log entries
• Service dependencies
• Memory and CPU usage
• Service start time

Method 3: Check Running Services with service Command

On older systems or for compatibility, use the service command:

# Check service status
service servicename status

# List all services (if available)
service --status-all

This provides compatibility with older init systems.

Method 4: Automated Running Service Monitoring with Zuzia.app

Manually checking running services works for occasional verification, but for production servers, you need automated monitoring that alerts you when services stop. Zuzia.app provides comprehensive service monitoring through scheduled command execution.

Setting Up Automated Service Monitoring

1. Add Scheduled Task in Zuzia.app Dashboard

   • Navigate to your Linux server in Zuzia.app
   • Click "Add Scheduled Task"
   • Choose "Command Execution" as the task type

2. Configure Service Check Command

   • Enter command: systemctl list-units --type=service --state=running
   • Set execution frequency: Every 15 minutes (recommended)
   • Configure alert conditions: Alert when critical services are missing
   • Set up filters for specific services if needed

3. Set Up Notifications

   • Choose notification channels (email, webhook, Slack, etc.)
   • Configure alerts when critical services stop
   • Set up alerts when unexpected services start
   • Configure escalation rules for critical service failures

Monitor Service Status Changes

Track service status changes over time:

# Running services with timestamp
echo "$(date): $(systemctl list-units --type=service --state=running --no-pager | wc -l) services running"

Zuzia.app stores all command outputs in its database, allowing you to track service status changes and identify patterns over time.

Method 5: Advanced Service Monitoring Techniques

Monitor Specific Critical Services

To monitor specific critical services:

# Check web server services
systemctl is-active nginx
systemctl is-active apache2

# Check database services
systemctl is-active mysql
systemctl is-active postgresql

# Check cache services
systemctl is-active redis
systemctl is-active memcached

This helps ensure critical services are always running.

Compare Service Lists Over Time

By storing service lists in Zuzia.app, you can compare current running services with previous lists to detect new services or stopped services.

Detect Failed Services

To identify services that have failed:

# List failed services
systemctl --failed

# Check for failed services
systemctl list-units --type=service --state=failed

Failed services require immediate attention as they indicate problems.

Real-World Use Cases for Service Monitoring

Critical Service Availability

Monitor critical services to ensure availability:

# Check critical services
for service in nginx mysql redis; do
  if systemctl is-active $service >/dev/null 2>&1; then
    echo "$service is running"
  else
    echo "ALERT: $service is not running"
  fi
done

Set up Zuzia.app to check critical services every 5 minutes and alert immediately if any stop.

Unauthorized Service Detection

Detect unauthorized services:

# Compare current services with baseline
systemctl list-units --type=service --state=running --no-pager | awk '{print $1}' | sort > /tmp/current-services.txt
diff /tmp/baseline-services.txt /tmp/current-services.txt

Set up Zuzia.app to check services regularly and alert when unexpected services are detected.

Service Health Monitoring

Monitor service health over time:

# Count running services
systemctl list-units --type=service --state=running --no-pager | wc -l

# Track service count trends

Use Zuzia.app's historical data to track service availability trends.

Best Practices for Service Monitoring

1. Monitor Services Regularly

Check running services at least every 15-30 minutes for active monitoring. Less critical systems can be checked every hour. Use Zuzia.app automated monitoring to ensure regular checks.

2. Track Service Status Changes

Use Zuzia.app's historical data to track service status changes over time. Understanding when services stop or start helps detect problems early.

3. Monitor Critical Services More Frequently

Monitor mission-critical services more frequently (every 5-15 minutes) than less critical services. Set up dedicated monitoring tasks for critical services.

4. Maintain Baseline Service List

Maintain a baseline list of expected running services. Compare current services with baseline to detect unauthorized services quickly.

5. Review Audit Results Promptly

Review service monitoring results promptly and investigate any stopped critical services immediately. Service failures can cause system-wide problems.

Troubleshooting Common Service Monitoring Issues

Services Not Showing

If services are not showing:

1. Check systemd is running: systemctl status
2. Verify command syntax: Ensure systemctl command is correct
3. Check permissions: Some commands require root privileges
4. Verify service exists: systemctl list-unit-files | grep servicename

Service Stopped Unexpectedly

If a service stops unexpectedly:

1. Check service status: systemctl status servicename
2. Review service logs: journalctl -u servicename -n 50
3. Check dependencies: systemctl list-dependencies servicename
4. Restart service: systemctl restart servicename

Unexpected Services Running

If unexpected services are detected:

1. Identify the service: systemctl status servicename
2. Verify if service is authorized
3. Check when service was started: systemctl show servicename -p ActiveEnterTimestamp
4. Investigate potential security breach

FAQ: Common Questions About Monitoring Running Services

How often should I check running services on Linux?

We recommend checking running services every 15-30 minutes for active monitoring. Use Zuzia.app automated monitoring to check services continuously without manual intervention. Less critical systems can be checked every hour.

What should I do if a critical service stops running?

If a critical service stops, immediately investigate: check service status and logs, verify dependencies, restart the service if appropriate, and investigate root cause to prevent recurrence. Use Zuzia.app to monitor the service and receive alerts when it stops again.

Can I monitor specific services only?

Yes, you can modify commands to check specific services: systemctl is-active nginx mysql redis for multiple services, or create dedicated monitoring tasks for each critical service. This helps focus monitoring on important services.

How can I see service status changes over time?

Zuzia.app stores all service status data historically in its database, allowing you to view service status changes over time. You can see historical data showing which services were running on different dates, identify when services stopped or started, and track service availability trends.

What's the difference between active and running service status?

"Active" means the service is enabled and configured, while "running" means the service process is currently executing. A service can be active but not running (configured but stopped), or running but not active (process running but not managed by systemd).

Can I monitor services across multiple Linux servers?

Yes, Zuzia.app allows you to add multiple servers and monitor running services across all of them simultaneously. Each server executes service check commands independently, and all results are stored in Zuzia.app's database for centralized monitoring and comparison.

Does Zuzia.app use AI to analyze service patterns?

Yes, if you have Zuzia.app's full package, AI analysis is enabled. The AI can detect patterns in service failures, identify services that frequently stop, predict potential service issues before they occur, and suggest optimizations based on historical service data and machine learning algorithms.