Libro sobre Proxmox maestria
Proxmox HA- Zero Downtime
Resource-level fencing prevents the same cluster-related services or resources from starting on all nodes in the cluster simultaneously. Node-level fencing makes sure that the node in question does not run any services at all by simply power cycling the node with the help of a managed PDU or IPMI. This method is also known as STONITH or Shoot The Offending Node In The Head. There are several types of fencing devices, such as a network-managed switch, APC master switch, Dell drac card, and so on. In this chapter, we are going to use APC-managed PDU AP7921 to set up device-based fencing. AP7921 is completely tested with Proxmox and very much dependable. Also, setting up fencing with PDU is very simple. If you would like to try setting up fencing using other methods, visit the Proxmox Wiki at https://pve.proxmox.com/wiki/Fencing.
We can summarize the requirements of device-based fencing and HA setup as follows:
A minimum of three properly set up and updated Proxmox nodes.
Currently, a maximum of 16 Proxmox nodes per cluster can be used for HA.
High Availability configuration in Proxmox is a five-step process as follows:
Before we set up fencing and Proxmox HA, we have to make sure that nodes can boot immediately after a power cycle or power loss. Usually, this feature is disabled by default, as shown in the following screenshot:
Restore on AC Power Loss Stay Off
Power On Last State