What Is Warm Reboot?

Why Do We Need Warm Reboot?

Most network faults in the industry are caused by software bugs, which may trigger device restarts, causing service interruption.

If a device software bug occurs, the traditional reboot solution may cause frequent training interruptions and training rollback to the status at the backup time point, wasting training results.

The warm reboot function controls the OS and forwarding chip during the device restart to ensure that the forwarding chip works continuously during the OS restart. This reduces the traffic interruption time to less than 10s and ensures no interruption of AI training tasks.

What Are the Differences Between Warm Reboot and Traditional Reboot?

Warm reboot can be triggered in either of the following modes:

• When restarting a device, you can run the corresponding command to trigger the warm reboot function.
• When a fault occurs and the warm reboot conditions are met, the device automatically triggers the warm reboot function and restarts.

Difference between warm reboot and traditional reboot:

• Traditional reboot: The device restarts, and the forwarding is interrupted for more than 120s.
• Warm reboot: The device restarts immediately, and the forwarding is interrupted for less than 10s.

How Does Warm Reboot Work?

The working mode varies according to the warm reboot trigger mode.

1. When restarting a device, you can run the corresponding command to trigger the warm reboot function.

   Proactive reboot requires pre-check and preprocessing before the restart.

   The pre-check is to check whether the system allows warm reboot.

   The preprocessing is to enable the system to perform necessary operations before the warm reboot.

   After the pre-check and preprocessing are successful, the device restarts in warm reboot mode.

2. When a fault occurs and the warm reboot conditions are met, the device automatically triggers the warm reboot function and restarts.

   The system determines the cause of the fault and triggers a warm reboot if the warm reboot requirements are met.

How Do I Select a Reboot Mode?

If a serious fault occurs in the system, for example, a hardware fault occurs, traditional reboot may be the only choice.

If a minor problem occurs in the system, for example, some services are abnormal, you can try warm reboot to solve the problem. In addition, the warm reboot mode is recommended when the system interruption time needs to be minimized because the device can be quickly restarted in this mode.