Automated System Health Checker

Project Information

Category: Linux Administration / DevOps
Client: Personal Project
Project date: November 2025
Technologies: Bash, Linux, System Monitoring

Project Overview

Enterprise-grade bash script for automated system health monitoring, performance analysis, and security log auditing. This tool provides comprehensive reporting capabilities for proactive Linux server management, helping identify potential issues before they impact system performance or security.

View Full Documentation Download Script

Key Features

CPU Monitoring: Real-time CPU usage tracking with threshold alerts and top process identification
Memory Analysis: Comprehensive RAM usage monitoring with detailed breakdown and memory-intensive process detection
Disk Management: Filesystem usage monitoring with automatic alerts for critical storage levels
Process Tracking: Running process analysis with zombie process detection and resource usage reports
Security Logs: Authentication log analysis, failed login tracking, and sudo command auditing
Network Status: Active connection monitoring and listening port identification
Email Reports: Automated email delivery of health reports to system administrators
Detailed Logging: Timestamped reports with color-coded status indicators for easy analysis

Technologies & Skills

Bash Scripting Linux Administration System Monitoring Security Auditing Process Management Automation DevOps Cron Jobs

CPU Usage Analysis Function

check_cpu() {
    echo -e "${BLUE}[CPU USAGE]${NC}"
    
    cpu_usage=$(top -bn1 | grep "Cpu(s)" | sed "s/.*, *\([0-9.]*\)%* id.*/\1/" | awk '{print 100 - $1}')
    
    echo "Current CPU Usage: ${cpu_usage}%"
    
    if (( $(echo "$cpu_usage > $CPU_THRESHOLD" | bc -l) )); then
        echo -e "${RED}WARNING: CPU usage is above ${CPU_THRESHOLD}%${NC}"
    else
        echo -e "${GREEN}Status: Normal${NC}"
    fi
    
    echo "Top 5 CPU-consuming processes:"
    ps aux --sort=-%cpu | head -6
}

Memory Monitoring Function

check_memory() {
    echo -e "${BLUE}[MEMORY USAGE]${NC}"
    
    memory_usage=$(free | grep Mem | awk '{print ($3/$2) * 100.0}')
    
    echo "Current Memory Usage: ${memory_usage}%"
    
    if (( $(echo "$memory_usage > $MEMORY_THRESHOLD" | bc -l) )); then
        echo -e "${RED}WARNING: Memory usage is above ${MEMORY_THRESHOLD}%${NC}"
    fi
    
    free -h
    ps aux --sort=-%mem | head -6
}

Security Log Analysis Function

check_security_logs() {
    echo -e "${BLUE}[SECURITY LOG ANALYSIS]${NC}"
    
    failed_logins=$(grep "Failed password" /var/log/auth.log | grep "$(date +%b' '%d)" | wc -l)
    echo "Failed login attempts today: $failed_logins"
    
    if [ "$failed_logins" -gt 10 ]; then
        echo -e "${RED}WARNING: High number of failed login attempts${NC}"
    fi
    
    echo "Recent sudo commands (last 10):"
    grep "sudo" /var/log/auth.log | tail -10
}

Installation & Usage

Setup Commands

# 1. Download the script
wget https://example.com/system_health_checker.sh

# 2. Make it executable
chmod +x system_health_checker.sh

# 3. Run the health check
./system_health_checker.sh

# 4. Schedule automatic checks (every 6 hours)
crontab -e
# Add: 0 */6 * * * /path/to/system_health_checker.sh

Configuration

Edit the configuration variables at the top of the script to adjust thresholds and email settings:

Configuration Variables

CPU_THRESHOLD=80        # Alert when CPU exceeds 80%
MEMORY_THRESHOLD=80     # Alert when memory exceeds 80%
DISK_THRESHOLD=85       # Alert when disk usage exceeds 85%
EMAIL_RECIPIENT=""      # Optional email notifications

Business Value & Impact

Proactive Monitoring

Identifies potential issues before they impact users, reducing downtime and improving system reliability.

Cost Savings

Automated monitoring reduces manual oversight needs and prevents costly system failures through early detection.

Security Enhancement

Regular security log analysis helps detect unauthorized access attempts and maintain compliance standards.

Skills Demonstrated

System Administration

Linux system monitoring and diagnostics
Process management and analysis
Resource utilization tracking
Performance optimization

Scripting & Automation

Advanced Bash scripting
Automated reporting systems
Error handling and logging
Schedule automation with cron

Security & Compliance

Authentication log analysis
Security event monitoring
Intrusion detection awareness
Audit trail management

DevOps Practices

Proactive monitoring strategies
Alert threshold configuration
Documentation and reporting
Incident prevention