After an update, all administrators face the question of whether the node should be rebooted or not. The Proxmox upgrade process is usually very informative and tells us whether the node really needs a reboot. Most of the updates do not require any reboot. They are simply packaged updates. But some upgrades, such as kernel releases, newer grubs, and security patches, will require a node reboot every time. The exact method of rebooting depends on the environment, number, and nature of the VMs stored per node. In this section, we will see the most widely used method, which is by no means the only method.
For minimal virtual machine downtime, we can live-migrate all the VMs from a node to a different node, and then migrate them back to the original node. As of Proxmox VE 5.0, there is a nice GUI feature addition to instruct all VM migrations with a menu instead of selecting and migrating one VM at a time. The feature is under the Bulk Actions drop-down menu in the top-right corner of the GUI, as shown in the following screenshot:
As you can see from the previous screenshot, we can also start or stop all virtual machines. The selected action will only take place on a selected node from the left-hand navigation pane of the GUI. If the Proxmox node requires a reboot after an update, we can select Bulk Stop from the Bulk Actions drop-down menu to shut down all VMs in the node, and then restart the node. After the node restarts, start all VMs by clicking on Bulk Start under the drop-down menu.
The official Proxmox forum is also a great place to hang out to get information on issues due to updates. This is also a great place to learn about fixes posted by Proxmox developers if there are any issues with the released update.
Visit the official Proxmox forum at the following link: