You do not need to ungroup HA devices during the upgrade. You can manually perform an active/standby switchover to ensure that the upgrade takes place only on the standby device. This minimizes the risk of business disruption due to network failures.

Session sync failures may occur during cross-version upgrades. An HA switchover may cause temporary service fluctuations. If one-way application control is implemented, an HA switchover may cause reverse connections in scenarios where persistent connections and ALG protocols exist. This may cause service interruption and require service reconnection for recovery.

Procedure

Step 1.Before the upgrade starts, manually synchronize the configuration on the active device, perform an active/standby switchover, and check the service status.

Step 2.Check the synchronization report on the active device. If the synchronization is successful, continue the upgrade. If it fails, locate the failure cause and resolve the configuration differences between the two devices.

Step 3.Back up the configuration of the active and standby devices to avoid configuration loss.

Step 4.If preemption is enabled, disable it on both devices to prevent active/standby switchover issues during the upgrade.

Step 5.Upgrade the standby device. If both devices are active, manually switch one to standby. If the upgrade fails, contact a technical support representative to troubleshoot issues or roll back as soon as possible. Business services are carried by the other device and are not affected.

Step 6.After the standby device is upgraded and restarted, wait a few minutes. Then, check the session difference between the active and standby devices, or check whether critical business sessions have been synchronized between the devices. If they are synchronized, perform an active/standby switchover and check the service status on the new active device.

Note: Sessions may fail to be synchronized due to version differences between the active and standby devices. Therefore, after the active/standby switchover, some services may be interrupted and need to be restored.

Step 7.Make sure that the services are normal on the new active device and then upgrade the new standby device. If the upgrade fails, contact a technical support representative to troubleshoot issues or roll back the device. If you need to roll back, roll back the current standby device first. Then, perform an active/standby switchover and roll back the new standby device. Make sure that the rollback takes place only on the standby device.

Step 8.After the standby device is upgraded, view the report to check whether synchronization is successful on the active device. If it fails, perform manual synchronization. If it still fails, troubleshoot issues.

Step 9.If the synchronization is successful, you can check the service status.

Step 10.If preemption is disabled before the upgrade, enable it now.