A comprehensive system health check script for Linux servers, designed to verify optimal system configuration for high-performance environments.

This script checks various system settings and configurations to ensure your Linux server is optimally configured. It features color-coded output to easily identify passing and failing checks, and organizes checks into logical categories.

The script verifies the following aspects of your system:

• TCP Buffer Sizes: Checks for optimal TCP memory buffer configurations
• TCP Optimization: Validates congestion control algorithms and other TCP performance settings
• Kernel Optimization: Verifies timer migration, hung task timeout, and other kernel parameters
• Virtual Memory Tuning: Checks swappiness, memory maps, dirty ratio, and other VM subsystem parameters
• Solana Specific Tuning: Validates network buffer settings required for optimal Solana node performance
• CPU Governor Settings: Ensures CPU cores are set to performance governor mode
• CPU Performance: Verifies that CPU boost/turbo is enabled
• CPU Driver: Ensures that the p-state CPU scaling driver is being used
• Memory Management: Confirms swap is disabled
• Security Services: Checks that fail2ban is installed, enabled, and running
• System Updates: Validates that there are no more than 5 package updates pending
• Automatic Updates: Verifies that unattended upgrades and automatic updates are disabled
• System Reboot Status: Checks if Ubuntu system requires a reboot and fails if a reboot is needed
• Time Synchronization: Ensures some form of NTP time synchronization is active
• SSH Security: Verifies SSH is configured securely with root login and password authentication disabled
• Log Management: Checks for proper logrotate configuration for Solana services

# Basic usage (requires root/sudo)
sudo ./health_check.sh

# Quiet mode (only show final results)
sudo ./health_check.sh --quiet
sudo ./health_check.sh -q

# Use a custom configuration file
sudo ./health_check.sh --config /path/to/custom-config.json

# Display help
./health_check.sh --help

The script uses a JSON configuration file (config.json by default) that contains all the expected values for the checks and allows enabling/disabling specific checks. This allows you to customize the script behavior without modifying the script itself.

You can specify a custom configuration file with the -c or --config option:

sudo ./health_check.sh --config /path/to/custom-config.json

The configuration file is structured as follows:

{
  "checksToRun": {
    "sysctlParams": true,
    "cpuGovernor": true,
    "cpuBoost": true,
    "cpuDriver": true, 
    "swapStatus": true,
    "packageUpdates": true,
    "ntpSync": true,
    "fail2ban": true,
    "sshConfig": true,
    "solanaLogrotate": true,
    "unattendedUpgrades": true,
    "rebootStatus": true
  },
  "sysctlChecks": {
    "Category Name": {
      "sysctl.parameter": "expected value"
    }
  },
  "systemChecks": {
    "cpu": {
      "governor": "performance",
      "boost": "enabled",
      "driver": "pstate"
    },
    "security": {
      "fail2ban": {
        "enabled": true,
        "running": true
      },
      "ssh": {
        "rootLogin": "no",
        "passwordAuth": "no"
      }
    },
    "updates": {
      "maxPendingUpdates": 5,
      "unattendedUpgrades": false
    },
    "memory": {
      "swapEnabled": false
    },
    "time": {
      "ntpEnabled": true
    },
    "logs": {
      "solanaLogrotate": true
    }
  }
}

To disable specific checks, set their values to false in the checksToRun section:

"checksToRun": {
  "sysctlParams": true,  
  "cpuGovernor": true,
  "cpuBoost": true,
  "cpuDriver": false,    # This check will be skipped
  "swapStatus": true,
  "packageUpdates": false, # This check will be skipped
  "ntpSync": true,
  "fail2ban": false,     # This check will be skipped
  "sshConfig": true,
  "solanaLogrotate": true,
  "unattendedUpgrades": true,
  "rebootStatus": true
}

You can also modify any of the expected values in the sysctlChecks and systemChecks sections to match your specific system requirements. For example:

"cpu": {
  "governor": "powersave",  # Changed from "performance"
  "boost": "disabled",      # Changed from "enabled"
  "driver": "pstate"
}

• Linux-based operating system
• Root/sudo access
• Bash shell

The script provides color-coded output for easy interpretation:

• 🟢 Green: Passing checks
• 🔴 Red: Failing checks that need attention
• 🟡 Yellow: Warnings or skipped checks
• 🔵 Blue: Informational messages

• For TCP congestion control, the script expects "westwood" but will accept "bbr" with a warning
• For kernel.pid_max, the script checks if the value is equal to or greater than the expected value
• For vm.swappiness, the script accepts any value of 30 or lower
• CPU boost check handles both Intel and AMD-specific boost mechanisms
• NTP check supports multiple time synchronization methods (systemd-timesyncd, chronyd, ntpd, OpenNTPD)
• Package update checker automatically detects apt, dnf, yum, pacman, or zypper package managers