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How to Automatically Restore PM2 Apps After Server Reboot (Managed Hosting)<

How to Automatically Restore PM2 Apps After Server Reboot (Managed Hosting)

Overview

On managed servers without root access, PM2 processes do not automatically restart after a server reboot. This can cause all Node.js / Next.js applications to go offline.

To solve this, we use:

  • PM2 process snapshot (pm2 save)
  • Crontab @reboot to restore apps
  • Optional watchdog cron to ensure uptime

Step 1: Save Current PM2 State

Run this once after all applications are running:

pm2 save

This creates a snapshot file (~/.pm2/dump.pm2) containing all running apps.

Step 2: Find the Correct PM2 Path

Cron jobs run in a limited environment, so you must use the full path to PM2.

Run:

which pm2

Example output:

/home/username/.volta/bin/pm2
/usr/bin/pm2
/home/username/.nvm/versions/node/v18/bin/pm2

Copy the full path returned and use it in your cron job.

Step 3: Add Crontab Entry for Reboot

Edit your crontab:

crontab -e

Add the following line (replace /full/path/to/pm2):

@reboot /usr/bin/env bash -lc '/full/path/to/pm2 resurrect >> $HOME/pm2_reboot.log 2>&1'

This ensures that all saved PM2 applications are restored automatically after a server restart.

Step 4: Add Watchdog Cron (Optional but Recommended)

This cron job ensures that if PM2 or apps stop unexpectedly, they are restored.

*/15 * * * * /usr/bin/env bash -lc '/full/path/to/pm2 resurrect >> $HOME/pm2_watchdog.log 2>&1'

This runs every 15 minutes and has minimal performance impact.

Alternative: Using Dynamic Path (Optional)

If your environment supports it, you can dynamically resolve PM2:

@reboot /usr/bin/env bash -lc '$(which pm2) resurrect'

Note: This may not work on all managed hosting environments due to PATH limitations. Using a fixed full path is more reliable.

How It Works

  • pm2 save → stores current apps
  • pm2 resurrect → restores saved apps
  • @reboot → runs on server startup
  • cron → ensures recovery if something fails later

Testing

Test manually without reboot:

pm2 kill
pm2 resurrect

Check logs after reboot:

cat $HOME/pm2_reboot.log

Verify running apps:

pm2 list

Important Notes

  • Always run pm2 save after adding/removing apps
  • Use absolute paths in cron for reliability
  • Avoid relying on ~ or PATH in cron
  • Logs help debug issues after reboot

Summary

By combining PM2 snapshot and cron jobs, you ensure that all Node.js applications automatically recover after server restarts, even without root access.

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