Designing a reliable and high-performance Proxmox VE cluster depends heavily on one thing — your storage architecture. Whether you’re running a small 3-node setup or scaling to a 4-node infrastructure, the storage layer determines how well your VMs perform, how resilient your environment is, and how simple maintenance becomes.
This guide explores the best storage options for 3-node and 4-node Proxmox clusters, with clear recommendations for Ceph, ZFS replication, and TrueNAS SAN configurations.
Why Storage Matters in Proxmox VE Clusters
Proxmox VE is an open-source virtualization platform built on KVM and LXC, with native support for high availability (HA) and software-defined storage.
But not all storage backends deliver the same reliability or performance — especially in small clusters with limited nodes.
Your storage decision should consider:
Performance requirements — how many VMs and IOPS your workload demands
Resilience — how much downtime or data loss is acceptable
Scalability — whether you plan to expand beyond three or four nodes
Budget and complexity — balancing cost vs. manageability
Best Storage Options for a 3-Node Proxmox VE Cluster
Running Proxmox on three nodes is a popular entry-level setup — ideal for small businesses, edge sites, and labs. However, storage redundancy can be tricky at this size. Here are your best options:
Option 1: Ceph Distributed Storage (3 Replicas)
Ceph is Proxmox’s native distributed storage system. It provides a unified, self-healing storage pool shared across all nodes.
Pros
True high availability with data replicated across nodes
Seamless integration in Proxmox GUI
Fully redundant and scalable storage backend
Cons
Resource-intensive — requires fast NVMe disks and ≥10 GbE networking
On a 3-node setup, you lose redundancy when one node is down
Verdict
Ceph works on three nodes, but it’s tight.
You’ll need strong hardware and good networking to maintain performance.
It’s best suited if you plan to grow to 4 or 5 nodes later.
Option 2: ZFS Local Storage with Replication
ZFS replication offers the best blend of performance and simplicity for small clusters.
Each node uses local ZFS storage (SSD or NVMe), and Proxmox replicates VMs to another node at configurable intervals — even as frequently as every minute.
Pros
Local disk speed with asynchronous replication
No external SAN or complex setup
Easy to maintain and scale
Cons
Not true live HA — failover requires VM restart
Risk of up to 1 minute of data loss between replications
Verdict
Perfect for small 3-node clusters with 50–100 VMs.
With 1-minute replication and 10 GbE networking, failover downtime is only 1–2 minutes.
An excellent trade-off between simplicity, speed, and reliability.
Option 3: External SAN or NAS (TrueNAS, iSCSI, NFS)
If uptime is critical, a dedicated NAS or SAN like TrueNAS, Synology, or Dell EMC can act as centralized shared storage.
Pros
Proven enterprise stability
Native Proxmox HA support with shared LVM or ZFS over iSCSI
Easy to expand capacity
Cons
Costlier setup — requires extra hardware and dual controllers for redundancy
Network latency can impact VM I/O
Verdict
For production environments where downtime is not acceptable, a dual-controller SAN is one of the most stable and mature solutions.
Recommended 3-Node Setup Summary
| Storage Option | HA Support | Performance | Complexity | Ideal Use |
|---|---|---|---|---|
| Ceph (3× replication) | Full | High | High | Growing clusters |
| ZFS Replication | Partial | Very High | Low | SMBs / cost-effective HA |
| External SAN (iSCSI/NFS) | Full | Medium | Medium | Enterprise setups |
Pro Tip: Start with ZFS replication for simplicity, and move to Ceph once you scale beyond three nodes.
Best Storage Options for a 4-Node Proxmox VE Cluster
Adding a fourth node unlocks new architectural possibilities — and significantly improves fault tolerance.
You can now safely run Ceph, dedicate a node for storage, or even mix compute and backup roles.
Option 1: 4-Node Ceph Cluster (Full HA Recommended)
With 4 nodes, Ceph becomes the top recommendation.
You can run 3× replication while maintaining fault tolerance even during maintenance or node loss.
Pros
True shared storage across all nodes
Automatic data healing and rebalancing
Supports live migration and zero-downtime HA
Example Specs
| Component | Recommendation |
|---|---|
| Disks | 2× NVMe + 4–6× SSD per node |
| Memory | ≥ 128 GB per node |
| Network | Dual 10 GbE (cluster + public) |
Cons
Higher learning curve
Requires tuning for best performance
Verdict
If your 4 nodes have fast SSD/NVMe and 10 GbE, Ceph is the gold standard.
It’s scalable, fault-tolerant, and built directly into Proxmox.
Option 2: 3 Compute Nodes + 1 Storage Node (TrueNAS or ZFS over iSCSI)
If one node has larger storage or lower CPU/RAM, convert it into a dedicated storage server.
Run TrueNAS, ZFS over iSCSI, or even Proxmox Backup Server on it.
Your 3 main nodes act as compute servers, accessing centralized shared storage.
Pros
Simplifies compute nodes (no Ceph daemons)
Centralized snapshots, compression, and backups
Works with Proxmox HA and live migration
Cons
The storage node becomes a single point of failure unless mirrored
Slightly higher I/O latency
Verdict
An ideal setup for small to medium business clusters that need stable shared storage without Ceph complexity.
Option 3: ZFS Replication Mesh Across 4 Nodes
If you want to keep costs minimal and maintain high local performance, create a replication mesh using ZFS send/receive.
Each node replicates its VMs to another node, forming a ring or star topology.
Pros
Local NVMe speed
Easy to manage
Low cost
Cons
No live HA (VM restart required)
Asynchronous data sync
Verdict
Best for environments where uptime is important but not mission-critical — such as development, testing, or SMB workloads.
Option 4: Hybrid Setup (Ceph + Backup Node)
You can also combine strategies — for example, run a 3-node Ceph cluster and use the 4th node for:
Ceph Monitor / Manager services
Proxmox Backup Server (PBS)
Off-cluster replication or cloud sync
Verdict
This hybrid setup strengthens both redundancy and data protection, making it great for small enterprise clusters.
Recommended 4-Node Setup Summary
| Goal | Recommended Design | Benefits |
|---|---|---|
| Full HA, production-grade | 4-node Ceph cluster | Real-time redundancy, live migration |
| Simple & centralized | 3 compute + 1 storage (TrueNAS/ZFS) | Easier management, stable performance |
| Budget-friendly | 4-node ZFS replication | Fast local I/O, low cost |
| Backup & resilience | 3 Ceph + 1 PBS node | Extra redundancy and offsite backup |
Final Recommendations
For most modern Proxmox VE deployments:
If you’re running 3 nodes, start with ZFS local storage + 1-minute replication for simplicity and great performance.
If you’re running 4 nodes, upgrade to a Ceph cluster with NVMe storage and 10 GbE networking for full high availability.
As your infrastructure scales, you can always transition smoothly from ZFS replication → Ceph distributed storage without major redesign.
Key Takeaways
ZFS replication is the best low-cost HA solution for 3-node clusters.
Ceph becomes optimal from 4 nodes upward, offering live migration and fault tolerance.
TrueNAS or iSCSI storage nodes remain a solid choice for centralized management and ease of use.
Always use 10 GbE networking and SSD/NVMe drives for best performance.