When and how to reboot safely

Topic: Servers linux

Schedule a reboot during a maintenance window; notify users, stop or drain services if needed, run reboot or shutdown -r, and verify the system and services after boot. Use this when applying kernel or critical updates, or recovering from a hung state.

Intent: How-to

Quick answer

  • Notify users and schedule a window. Stop non-essential services or put load balancers in maintenance; optionally run needrestart -u to see what will be restarted after reboot.
  • shutdown -r +5 'Reboot in 5 min' schedules reboot and broadcasts; cancel with shutdown -c. Or reboot now: sudo reboot. For delayed: shutdown -r 02:00.
  • After boot, check systemctl list-units --state=failed; verify critical services and connectivity; check logs (journalctl -b) for errors.

Prerequisites

Steps

  1. Plan and notify

    Choose a maintenance window; notify users. List services that must be up (systemctl list-units --type=service --state=running); plan to stop or drain if needed (e.g. put app in read-only or drain LB).

  2. Schedule or run reboot

    sudo shutdown -r +10 'Reboot in 10 min' or sudo shutdown -r 03:00 for a time. Cancel with shutdown -c. For immediate: sudo reboot. Ensure you have console or out-of-band access in case of boot failure.

  3. Verify after boot

    Check systemctl list-units --state=failed; start any required services that did not come up; run journalctl -b for boot logs; verify app and network.

Summary

Plan a maintenance window, notify users, and stop or drain services as needed. Use shutdown or reboot to restart; after boot, check for failed units and verify services. Use this for kernel updates or planned recovery.

Prerequisites

Steps

Step 1: Plan and notify

Schedule a window and notify users. Identify critical services; plan to stop or drain them if appropriate.

Step 2: Schedule or run reboot

sudo shutdown -r +10 "Reboot in 10 min"
# or
sudo reboot

Cancel with shutdown -c if needed.

Step 3: Verify after boot

systemctl list-units --state=failed
journalctl -b

Start any required services and verify connectivity.

Verification

  • Reboot completed; no unexpected failed units; critical services and apps are running.

Troubleshooting

Reboot hung — Use console or OOB; see How to troubleshoot boot failure. Service did not start — See Service won’t start.

Next steps

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