1. System Information
Understanding your system's hardware and software configuration is the first step in diagnostics.
Commands
uname -a # Displays kernel version and system architecture. lscpu # Provides detailed information about the CPU. lsblk # Lists all available block devices. lsusb # Shows USB devices connected to the system. lspci # Lists PCI devices.
2. CPU and Memory Diagnostics
Monitoring CPU and memory usage helps in identifying performance bottlenecks.
Real-time process monitoring.
htop
Real-time process monitoring.
Commands
vmstat # Reports virtual memory statistics. free -h # Displays memory usage. mpstat # Reports CPU usage.
3. Disk Usage and Health
Keeping track of disk usage and health is crucial for preventing data loss and ensuring efficient storage management.
Commands
df -h # Shows disk space usage. du -sh /path/to/directory # Displays the size of a specific directory. fdisk -l # Lists all partitions. smartctl -a /dev/sda # Checks the health of a disk (requires smartmontools). iostat # Reports CPU and I/O statistics.
4. Process and Service Management
Managing processes and services is essential for maintaining system stability.
Commands
ps aux # Lists all running processes. systemctl status service_name # Checks the status of a service. journalctl -u service_name # Views logs for a specific service. kill -9 process_id # Forces termination of a process. nice and renice # Adjusts process priority.
5. Logs and Monitoring
Analyzing logs and monitoring system activities can help in identifying issues and tracking system performance.
Commands
dmesg # Prints kernel ring buffer messages.
journalctl # Views systemd logs.
journalctl -u service_name # Views logs for a specific service.
tail -f /var/log/syslog # Continuously displays system log updates.
sar # Collects, reports, and saves system activity information (requires sysstat).
uptime # Shows how long the system has been running and load averages.