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System Startup

MOS provides dedicated hooks that are executed during system startup. These hooks allow controlled customization of the boot process.

Post-Start Script (post-start.sh)​

The Post-Start Script is executed after system startup has completed.

It runs after all storage pools are mounted and after all services have been started. This makes it suitable for tasks that require a fully initialized system environment.

📍 Script Location​

/boot/optional/scripts/post-start.sh

If this file exists, MOS will automatically execute it during every system startup.

⏱️ Execution Order​

The Post-Start Script is executed in the following phase:

  1. Storage pools are mounted
  2. Docker, LXC, VMs, and system services are started
  3. Post-Start Script is executed

At this stage, the full system environment is available.

🔧 Typical Use Cases​

  • Starting custom services or applications
  • Running system checks after startup
  • Applying configurations that depend on mounted storage
  • Interacting with containers or virtual machines
  • Triggering notifications after system startup
  • Custom monitoring or logging tasks

🧭 Recommended Usage​

While MOS provides startup scripts, Cron jobs are preferred for most automation tasks.

Cron jobs:

  • Are easier to maintain
  • Provide better logging and error handling
  • Can be scheduled or delayed
  • Reduce the risk of startup-related issues

Use the Post-Start Script only when an action must run immediately after system startup.

📌 Script Execution Notes​

  • The script does not need to be executable
  • No chmod +x is required
  • Script execution is handled internally by MOS

The script will be executed automatically as long as the file exists at the defined path.

⚠️ Important Notes​

  • Long-running commands may delay system readiness
  • Errors in this script can affect dependent services
  • Keep execution time short and predictable

✅ Summary​

  • Runs after all pools and services are available
  • Executed once during system startup
  • Intended for post-start initialization tasks
  • Cron jobs are preferred when possible
  • Part of the official MOS startup process

Parts of this documentation were created with the assistance of AI tools. All AI-generated content has undergone review, but it may still contain inaccuracies, omissions, or outdated information.