Proxmox VE Architecture
Proxmox VE is built on Debian Linux and integrates multiple open-source technologies into a unified virtualization platform. The architecture is designed for simplicity, performance, and scalability from single-server deployments to large clusters.
System Architecture
Proxmox VE Component Stack
Storage Architecture
Storage Stack & Options
Core Components
1. Web Interface (pveproxy)
The Proxmox web GUI is a single-page application that provides complete management capabilities through a browser. Accessible at https://hostname:8006.
- No plugins required: Pure HTML5/JavaScript, works on any modern browser
- Integrated console: VNC and SPICE consoles built-in
- Real-time updates: Live monitoring of resources and tasks
- Multi-language support: Available in 20+ languages
2. REST API (pvedaemon)
Everything in Proxmox can be controlled via the REST API, enabling automation and integration.
- JSON format: Easy to parse and work with
- Authentication: Ticket-based or API tokens
- CLI tools: pvesh command for API exploration
- Libraries: Python, Go, PHP SDKs available
3. Cluster Stack (Corosync + pmxcfs)
Proxmox uses Corosync for cluster membership and pmxcfs for replicated configuration storage.
- Corosync: Cluster communication and quorum management
- pmxcfs: Distributed configuration filesystem (SQLite-based)
- Automatic sync: Configuration changes propagate to all nodes
- Fencing: Watchdog-based fencing prevents split-brain
4. QEMU/KVM Integration
Proxmox uses QEMU with KVM acceleration for virtual machines, providing near-native performance.
- Hardware emulation: Complete PC hardware emulation
- VirtIO drivers: Paravirtualized drivers for best performance
- Live snapshots: Snapshot running VMs without downtime
- Migration: Online and offline migration support
5. LXC Integration
Linux Containers provide lightweight virtualization with minimal overhead.
- Namespaces: Process, network, mount, IPC isolation
- Cgroups: CPU, memory, I/O resource control
- AppArmor: Mandatory access control for security
- Template cache: Pre-built container templates
Networking Architecture
| Component | Function | Use Case |
|---|---|---|
| Linux Bridge | Layer 2 network switch | Standard VM/CT networking |
| Open vSwitch (OVS) | Advanced virtual switch | SDN, VXLAN, complex networking |
| Bonds | NIC aggregation | Redundancy, bandwidth aggregation |
| VLANs | Network segmentation | Isolate traffic, multi-tenancy |
| Firewall | Packet filtering | Security, per-VM rules |
Security Model
Multi-Layer Security
- Web Interface: HTTPS only, certificate authentication, role-based access control (RBAC)
- API Access: Token-based authentication, permission system, audit logging
- VM Isolation: Hardware-assisted virtualization, separate kernel, full isolation
- Container Security: AppArmor profiles, seccomp filters, unprivileged containers
- Network Security: Per-VM firewalls, security groups, VLAN isolation
- Storage: Encrypted volumes (LUKS), access controls, quota enforcement
Backup Architecture
Integrated Backup Solution
Proxmox Backup Server (PBS) provides enterprise-grade backup capabilities with deduplication and encryption.
- Snapshot-based: Consistent backups of running VMs/containers
- Compression: LZ4, ZSTD algorithms for efficient storage
- Deduplication: Block-level dedup saves storage space
- Encryption: End-to-end encryption for sensitive data
- Scheduling: Automated backup jobs with flexible timing
- Verification: Automatic backup verification
- Retention: Configurable retention policies
Understanding Proxmox VE's architecture helps in planning deployments, optimizing performance, and troubleshooting issues. The modular design allows you to choose components that fit your specific requirements.