In Proxmox Virtual Environment (PVE), maintenance mode can be enabled for individual cluster nodes. This is particularly useful when you want to perform updates, replace hardware, or troubleshoot an issue without VMs and containers continuing to use resources.
When should maintenance mode be enabled?
Enabling maintenance mode is useful in the following scenarios:
- Updates: If you want to install security updates or new packages, maintenance mode can prevent VMs from being restarted unexpectedly.
- Hardware maintenance: When replacing components such as disks, RAM, or network cards, the node often needs to be shut down. Maintenance mode ensures that VMs are migrated to other nodes.
- Debugging: During intensive troubleshooting, non-critical VMs should be moved away from the node so that analyses can be performed without compromising availability.
Benefits of manual migration
When maintenance mode is enabled, the system automatically migrates running resources—that is, active VMs and containers—to other available nodes in the cluster. Once maintenance is complete and maintenance mode is disabled, the resources automatically migrate back to the original node. This behavior is a major advantage over a purely bulk migration, which requires the resources to be moved back manually.
How to enable maintenance mode
In a Proxmox VE configuration with Cluster Manager (ha-manager), maintenance mode can be enabled from the command line. Replace pve with the name of your target node:
ha-manager crm-command node-maintenance enable pve
How to disable maintenance mode
Once the maintenance work is complete, you can usually return to normal operation using the same method:
ha-manager crm-command node-maintenance disable pve
Conclusion
Maintenance mode is an essential mechanism for safely and systematically maintaining Proxmox VE nodes. It minimizes downtime, enables automatic resource migration, and protects cluster high availability. Use it when planning updates, replacing hardware, or investigating errors.