High Availability Deep Dive

Overview

Proxmox VE High Availability (HA) provides automatic VM/container failover when a node fails. Essential for production workloads requiring uptime.

HA Architecture

Components

• HA Manager: Coordinates failover
• Fencing: Power cycles failed nodes
• Resource Groups: Priority VM placement

Quorum

# Check quorum
pvecm status
 
# View expected
pvecm e

Configure HA

Enable HA for VM

# Enable HA
ha-manager enable vm:100
 
# Set priority
ha-manager crm add production --vm 100 --priority 100

Configure Fencing

# Install fence agents
apt install fence-agents-all
 
# Configure via Web UI
# Datacenter -> HA -> Fencing

HA Groups

Create Group

# Create group
ha-manager group add production pve1 pve2 pve3
 
# Add node with priority
ha-manager group add production pve1 pve2 pve3
 
# Remove node
ha-manager group remove production pve3

Node Priority

# Set priority
ha-manager crm modify vm:100 --priority 100

HA Best Practices

1. Minimum 3 nodes
2. Separate power sources
3. Configure fencing
4. Test failover

Keywords

ha high-availability failover cluster quorum fencing

Related Articles

• Advanced
• Cluster
• High-Availability

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