https://drive.google.com/file/d/1qYUrxUr1QCrXGTx00iDGMgqoYUVdSNL5/view?usp=sharing

1. CPU and Memory Monitoring

top - Real-time Process Monitor

top                    # Interactive process viewer
top -p <PID>           # Monitor specific process

• Key columns: %CPU, %MEM, PID, COMMAND
• Interactive commands:
  • k → Kill process
  • r → Renice process
  • q → Quit

free - Memory Usage

free                   # Show memory in KB
free -m                # Show in MB
free -g                # Show in GB
free -s 3              # Update every 3 seconds
watch -d -n 5 free     # Highlight changes every 5 seconds

• Columns: total, used, free, shared, buff/cache, available
• Critical metric: available (not free) shows usable memory

2. I/O and CPU Detailed Monitoring

iostat - I/O Statistics

# Install sysstat package first
sudo yum install sysstat -y

iostat                 # CPU + disk I/O summary
iostat -d 2 8          # Disk stats every 2s, 8 times

• Key metrics:
  • %util → Device utilization (100% = bottleneck)
  • await → Average I/O wait time (ms)

mpstat - Per-CPU Statistics

mpstat                 # Average across all CPUs
mpstat -P ALL          # Per-CPU breakdown

• Identify: CPU imbalances or single-core bottlenecks

sar - System Activity Reporter