A hypervisor concentrates several services: if it is compromised or lost, every VM can be affected. Security and backups must therefore be planned before going into production.
How do I secure access to my Proxmox interface?
By replacing the initial passwords, enabling 2FA and restricting SSH and port 8006 to trusted sources.
- Replace all initial passwords and use unique secrets.
- Enable two-factor authentication for compatible Proxmox accounts.
- Create named accounts with minimum privileges rather than sharing
root. - Use a protected SSH key and keep a fallback session open throughout any SSH change.
- Restrict access to the administration ports, in particular SSH and
8006, to trusted addresses when your organisation allows it. - Do not expose the Proxmox interface behind a makeshift proxy configuration unless you fully understand TLS, WebSocket and security headers.
How do I update Proxmox without interrupting services?
By reading the release notes, backing up before any major upgrade and keeping reboots for a maintenance window.
- Read the release notes and back up before a major upgrade.
- Install stable updates in reasonable batches.
- Schedule a maintenance window for kernel or version changes.
- Only reboot after checking the status and console of the VMs.
- Do not mix repositories that are incompatible with your subscription or your Proxmox version.
How do I set up a multi-level firewall?
Proxmox provides rules at Datacenter, node and VM level. The guest system also has its own firewall. Start with a documented policy, allow your administration IP before enabling a restrictive policy, then test from a second connection.
Only open the ports the service needs: for example 80/443 for a web server. A database VM should generally not expose its port to the whole world.
Is a Proxmox snapshot enough as a backup?
A snapshot is not a standalone backup. It depends on the same storage and does not protect against the complete loss of the VDS.
Apply the 3-2-1 rule when the data matters:
- three copies of the data;
- two separate media or locations;
- one copy outside the VDS.
Schedule regular backups, encrypt sensitive data and monitor failures. Above all, regularly carry out a test restore on an isolated VM. A backup that has never been restored is no guarantee.
What should I monitor on a Proxmox VDS?
Storage space first and foremost, because full storage stops VMs and snapshots without warning.
At a minimum, monitor:
- disk space on the node and the VMs;
- CPU and RAM usage;
- backup status;
- availability of public services;
- disk, network and authentication errors;
- expiry of certificates and domain names.
Set up alerts before saturation is reached. Full storage can block VMs and make snapshot operations impossible.
How do I troubleshoot a fault methodically?
Start with the simplest: the service status in the customer area, then the network, then the VM itself.
The Proxmox interface no longer responds
First check the service status in the customer area, then test the IP and port 8006. Use SSH or the recovery console if available. Do not reset the network until you have recorded the current configuration.
A VM does not start
Read the failed task in Proxmox. Check disk space, locks, boot order, a missing ISO and available resources. Avoid deleting a disk just to ‘try something’: this can make the data unrecoverable.
A VM no longer has Internet access
Use its Proxmox console. Check the interface, address, route, DNS and firewall, then compare the IP/MAC pair with the one in the customer area. Follow the IP/MAC networking guide.
What information should I include in a support ticket?
To speed up the diagnosis, provide the service identifier, the VM ID, the time of the problem, the exact message, the tests carried out and any recent changes. Hide passwords, private keys and tokens: support never needs them.